MXPA99002785A - Cationic water-soluble polymer precipitation in salt solutions - Google Patents

Abstract

Compositions comprised of water, at least one precipitated cationic water-soluble polymer, an effective amount of at least one kosmotropic salt, and an effective amount of at least one chaotropic salt, wherein said chaotropic salt is present in an amount greater than 1%, by weight, based on the weight of said cationic water-soluble polymer.

Description

SOLUBLE POLYMER PRECIPITATION IN CATIONIC WATER IN SALT SOLUTIONS Field of the Invention This invention relates generally to aqueous compositions of certain salts, which contain water-soluble, cationic polymers, precipitates, methods for precipitating water-soluble polymers, cationics in aqueous solutions containing certain salts, methods for polymerizing monomers in aqueous solutions containing certain salts for forming water-soluble, precipitated cationic polymers, optionally precipitated as polymer dispersions, and methods for using water-soluble, cationic polymer compositions, precipitated in aqueous solutions of certain salts for various applications, eg, flocculation of suspended solids and soil conditioning.

Background of the Invention The cationic, water soluble, high molecular weight polymers are useful in a number of applications, for example, the flocculation of suspended solids, recovery of minerals from mining operations, manufacture of Ref. 029657 paper, oil recovery increased, soil conditioning, etc. In many cases, the polymers are provided to the user in the form of substantially dried polymer granules. The granules can be manufactured by the polymerization of water-soluble monomers in water to form a water-soluble polymer solution, followed by dehydration and grinding to form granules of water-soluble polymer.

Other means for isolating the polymer from the polymer solution is to precipitate the polymer by mixing the polymer solution with an organic solvent, for example, acetone or methanol which is a non-solvent for the polymer, then isolating the polymer by evaporation or filtration. However, in many cases, this method is inconvenient, expensive and dangerous due to the problem of handling large amounts of flammable organic solvent.

There have been a few reports of unusual precipitation behavior that refer to particular cationic polymers. Certain new cationic polyelectrolytes, called ionene polymers, are reported (D. Casson and A. Rembaum, Macromolecules, Vol. 5, No. 1, 1972, pp. 75-81) that are insoluble in either 0.4M potassium iodide. or potassium thiocyanate 0.4M. Poly (allyl ammonium chloride) is reported (T. Itaya et al., J. Polym. Sci., Pt. B: Polym. Phys., Vol. 32, pp. 171-177, 1994, and references 3, 5 and 6 here, also Macromolecules, Vol. 26, pp. 6021-6026, 1993) which precipitate in solutions containing the sodium salt of the p-ethylbenzenesulfonate, or p-propylbenzenesulfonate or naphthalenesulfonate. Poly (4-vinyl pyridine converted to a quaternary compound with butyl chloride and poly (allylammonium chloride) is reported (M. Satoh, E. Yoda, and J. Komiyama, Macromolecules, Vol. 24, pp. 1123- 27, 1991) which precipitates in Nal solutions and also in solutions containing the sodium salt of the p-ethylbenzenesulfonate, respectively.It has also been reported (-F, Lee and CC.Tsai, J. Appl. Polym. Sci., Vol. 52, pp. 1447-1458, 1994) that poly (trimethylacrylamidopropylammonium iodide) does not dissolve in 0.5M Na2Cl04 or 0.5M NaN03.

Water-soluble polymers can also be provided in the form of a water-in-oil emulsion or microemulsion, wherein the droplets of polymer solution are isolated from each other by the continuous phase, for example, oil, of the emulsion or microemulsion. The polymer emulsions can be used directly in the desired application. Although this mode of supply is convenient and can avoid the need for dehydration, the oil can be expensive and is often flammable; In addition, the oil may also present a secondary contamination problem. Alternatively, the emulsion may be precipitated in an organic liquid which is a solvent for water and oil, but is a non-solvent for the polymer, followed by isolation and drying to recover the dry polymer substantially. However, these precipitation methods can be disadvantageous for the same reasons mentioned above.

A first water-soluble polymer can also be dispersed in the presence of a second water-soluble polymer to form aqueous polymer dispersions, as taught in U.S. Pat. Nos. 4,380,600 and 5,403,883. Since the two polymers do not dissolve with each other, the first water-soluble polymer is said to form small globules, which are dispersed in the solution of the second water-soluble polymer. Optionally, the salt can be added to improve the flowability.

The polymers can also be precipitated in an aqueous salt solution. For example, U.S. Pat. No. 3,336,270 describes polymerization processes of monomers to form water-soluble polymers in aqueous solutions containing salt and tertiary butanol, wherein the polymer precipitates as these forms. The U.S. Patents Nos. 4,929,655 and 5,006,590; as well as EP 0 183 466 Bl and EP 0 630 909 Al, describes the polymerization of cationic water-soluble polymers in an aqueous solution, which contains a multivalent anionic salt and a polymeric dispentant, without the requirement of tertiary butanol . The aqueous solution of the multivalent anionic salt is a non-solvent for the polymer, so that the polymer precipitates like these forms. The polymer dispersant operates within the precipitation system by stabilizing the particles, but has no polymer deposition effect. The precipitation of the polymer depends on the functional group of the polymer and on the amount and identity of the salt. The structural units of the polymer which contain benzyl groups are more easily precipitated in the salt solution than the (meta) acrylamide structural units, which are themselves more easily precipitated than the structural units, such as (chloride). methacryloyloxyethyltrimethylammonium), then DMAEM.MeCl, which does not contain benzyl groups. Typical water-soluble, cationic polymers, for example, poly (methacryloyloxyethyltrimethylammonium chloride), then poly (DMAEM.MeCl), tend to be soluble at room temperature in aqueous solutions of multivalent anionic salts, such as those used in US patents 4,929,655 and 5,006,590. Compared to emulsions, the replacement of the oil with an aqueous salt solution is an advantage in the art because the aqueous salt solution is non-flammable and presents less of a secondary contamination problem. However, the presence of an aromatic benzyl group in the polymer can be a disadvantage from an economic and environmental perspective.

The polymers and monomers which contain hydrophobic groups, for example, benzyl can not themselves be hydrophobic, because they can have a high degree of water solubility. However, polymers with hydrophobic groups tend to be more easily precipitated in salt solutions than polymers without hydrophobic groups. Although the benzyl group can be replaced by a hydrophobic alkyl group as in EP 0 525 751 Al, it must be clearly advantageous to eliminate the need for these hydrophobic groups completely to avoid the cost and inconvenience of manufacturing the monomer, which contains the hydrophobic group. Accordingly, there is a need for compositions that can act as non-solvents for the typical cationic water-soluble polymers currently used in applications, such as water treatment, mining, papermaking, oil recovery, etc., which are relatively non-flammable, economical and non-toxic.

The effect of salts on the solubility of several substances in aqueous solution is well discussed in the scientific literature. The series "Hofmeister" classifies the anions according to their facility to increase or decrease the solubility of the substances in water. Although positions in the range may vary slightly, depending on the substance, a generally accepted range of anions is: Precipitation Solubility of one of a Electrolyte Electrolyte (cos otropic) (chaotropic) S042"~ HP042" > F "> Cl" > Br "> I" ~ C104"> SCN" It is well known that cosmotropic salts generally decrease the solubility of many substances in water. For example, the Hofmeister range apparently guides the choice of salts to precipitate cationic water soluble polymers, which contain hydrophobic groups, in U.S. Pat. Nos. 4,929,655 and 5,006,590, as well as EP 0 630 909 Al, EP 0 525 751 Al, and EP 0 657 478 A2, as demonstrated by their use of strongly cosmotropic salts containing sulfate and phosphate anions. On the other hand, chaotropic salts generally increase the solubility of the substances in water.

There are numerous means known to those skilled in the art to determine whether a particular salt is cosmotropic or chaotropic. Representative salts which contain anions, such as sulfate, fluoride, phosphate, acetate, citrate, tartrate and hydrogen phosphate are cosmotropic. Representative salts which contain anions, such as thiocyanate, perchlorate, chlorate, bromate, iodide, nitrate and bromide are chaotropic. Chloride anion is generally considered to be at approximately half the range of Hofmeister, being neither strongly chaotropic nor strongly cosmotropic. For these purposes, the inorganic salts which contain the chloride anion are neither chaotropic nor cosmotropic.

Small amounts of sodium thiocyanate, for example about 0.1% by weight, of the total, have been reported to be useful as stabilizers for polymer dispersions in EP 0 657 478 A2, where (NH4) 2S04 is used to deposit the polymer . Sodium thiocyanate and sodium iodide have been reported to be useful as stabilizers for water soluble polymer systems containing hydroxylamine, as in EP 0 514 649 Al. U.S. Pat. No. 3,234,163 teaches that small amounts of thiocyanate salts, preferably 0.1 to 1 percent, based on the weight of the polymer, are useful for stabilizing the polyacrylamide solutions. The thiocyanate salts are claimed to stabilize the polyacrylamide by preventing or retarding the decomposition of the molecular weight.

Many reports in the literature that refer to the Hofmeister range of salts have included studies of their effects on low molecular weight substances, which have relatively low water solubility. However, the Hofmeister range has also been observed when the substrates are water soluble, high molecular weight polymers. For example, the effect of various salts on the solubility of the water-soluble, synthetic polymers is explored by Shuj i Saito, J. Polym. Sci .: Pt. A, Vol. 7, pp. 1789-1802 (1969). This author discusses the effect of several anions on the solubility of the polymer and states "This anionic order appears to be independent of the type of countercations and is in accordance with the Hofmeister lyotropic series for anions". Similarly, in M. Leca, Polymer Bulletin, Vol. 16, pp. 537-534, 1986, the viscosity of the polyacrylamide, as determined in IN solutions of various salts, is found to increase in the order of HP042"< H20 < Br < N03"< I" = Br03"< C103" = SCNX Viscosities are reported to be higher in more chaotropic salt solutions than in less chaotropic, or cosmotropic salt solutions.

Certain anionic organic salts, such as hydrotropes and surfactants, also tend to increase the solubility of the substances in water. The manner in which organic anionic salts act to increase the solubility of substances in water generally depends on the identity of the organic portion. Salts with smaller organic portions tend to function as hydrotropes, while salts with larger organic groups tend to function as surfactants.

The ease of surfactants to increase the solubility of substances in water is well known. Compositions comprising sulfonated hydrocarbon surfactants and hydrophilic cationic polymers are described in U.S. Pat. No. 5,130,358. For the purposes of this invention, surfactants are defined as surface active agents that have the facility to reduce surface tension at an interface without requiring concentrations so large that the difference between the solute and the solvent is unclear.

Surprisingly, and contrary to the teachings cited above, it has now been found that many typical water-soluble cationic polymers, such as poly (DMAEM.MeCl), which does not contain hydrophobic groups, can be precipitated in aqueous solution by the presence of a mixture of a chaotropic salt, or an organic anionic salt, and a cosmotropic salt. Therefore, according to the invention, processes for precipitating cationic, water-soluble polymers are provided by mixing cationic, water-soluble polymers with at least one chaotropic salt, or anionic organic salt, and at least one cosmotropic salt. Also included in the present invention are compositions comprising water, at least one chaotropic salt, or anionic organic salt, at least one cosmotropic salt, and at least one water soluble, cationic precipitated polymer. Preferred are compositions in which the precipitated polymer is dispersed in the form of small droplets to produce a polymer dispersion. These polymer dispersions can be stabilized by a dispersant, which can be a different water-soluble polymer, and the precipitated polymer is preferably formed by polymerization of monomers in the salt solution, optionally in the presence of dispersant. Also described are processes for using these compositions which concentrate dispersions of suspended solids and condition the soil.

Brief Description of the Invention The present invention relates to cationic polymer compositions precipitated in solutions of chaotropic salts, and / or anionic organic salts, and cosmotropic salts, as well as processes for making and using the same. The cationic polymers may contain a hydrophobic group, but it is not required, so that modification of the polymer structure to cause precipitation in the salt solution, as tt in the prior art, is not necessary. Preferred are compositions in which the polymer is dispersed in the form of small droplets, and methods of making these polymer dispersions which may include dispersants are tt herein. A particularly preferred method is to form the polymer dispersion by polymerization of the monomers in solutions of the salts, optionally in the presence of one or more different water-soluble polymers, which act as dispersants. Also included are methods of using the compositions of the present invention for applications, such as flocculation of suspended solids, solid-liquid separations, mining, papermaking, soil conditioning, etc.

The embodiments of the present invention include compositions composed of water, at least one precipitated cationic water soluble polymer, an effective amount of at least one cosmotropic salt, and an effective amount of at least one chaotropic salt, wherein the chaotropic salt is present in an amount greater than 1%, by weight, based on the weight of the polymer soluble in cationic water; Preferred compositions are composed of water, at least one precipitated cationic water-soluble polymer, from 1% to 27% by weight, based on the total weight, of a sulfate salt, and from 1% to 200% by weight, based on in the total weight of the polymer, of a thiocyanate salt, wherein the precipitated cationic water-soluble polymer is composed of recurring units of a quaternary salt of a dialkylaminoalkyl (alk) acrylate). Also preferred are compositions, optionally containing a second water soluble polymer, in which the cationic water soluble polymer is precipitated as a dispersion.

Additional embodiments include processes comprising mixing, in any order, water, at least one cationic water-soluble polymer, an effective amount of at least one cosmotropic salt, and an effective amount of at least one chaotropic salt to form an aqueous composition. comprising at least one precipitated cationic water-soluble polymer, wherein the chaotropic salt is present in an amount greater than 1%, by weight, based on the weight of the cationic water-soluble polymer; Preferred embodiments include the processes comprising mixing, in any order, a cationic water-soluble polymer composed of recurring units of a quaternary salt of a dialkylaminoalkyl (alk) acrylate, from 1% to 200%, by weight based on total weight of the polymer, of a thiocyanate salt, and from 1% to 27%, by weight based on the total weight, of a sulfate salt, to form an aqueous composition comprising at least one precipitated cationic water-soluble polymer. Also preferred are processes which comprise mixing in a second water-soluble polymer.

Processes comprising the polymerization of at least one cationic monomer in an aqueous solution composed of an effective amount of at least one chaotropic salt and an effective amount of at least one cosmotropic salt, to form an aqueous composition comprising at least one a polymer soluble in precipitated cationic water; Preferred embodiments include processes comprising the polymerization of monomers composed of a quaternary salt of a dialkylaminoalkyl (alk) acrylate, in an aqueous solution composed of (a) from 0.1% to 250%, by weight based on the total weight of the monomer , of a thiocyanate salt and (b) from 1% to 28%, by weight based on the total weight, of a sulfate salt, to form an aqueous composition comprising at least one precipitated cationic water-soluble polymer. Processes are preferred in which the water-soluble cationic polymers are precipitated as a dispersion, optionally in the presence of a second water-soluble polymer.

The applications of the present invention include the processes of concentrating a dispersion of suspended solids, which comprise the dewatering of a dispersion of suspended solids by adding to the dispersion an effective amount of an aqueous composition composed of an effective amount of at least one salt chaotropic, an effective amount of at least one cosmotropic salt, and at least one polymer soluble in precipitated cationic water, and separation of the resulting concentrated dispersion, wherein the chaotropic salt is present in an amount greater than 1%, by weight, based on the weight of the polymer soluble in cationic water; Preferred embodiments include the processes of concentrating a dispersion of suspended solids, which comprise the dewatering of a biologically treated suspension by adding to the suspension an effective amount of a composition composed of at least one precipitated cationic water-soluble polymer, from 1% up to 27% by weight, based on the total weight, of a sulfate salt, and from 1% to 200% by weight, based on the total weight of polymer, of a thiocyanate salt, and separation of the resulting concentrated dispersion , wherein the precipitated cationic water-soluble polymer is composed of recurring units of a quaternary salt of a dialkylaminoalkyl (alk) acrylate. Other applications include soil conditioning processes, which comprise adding to the soil an amount for soil conditioning an aqueous composition composed of an effective amount of at least one chaotropic salt, an effective amount of at least one cosmotropic salt, and at least one polymer soluble in precipitated cationic water. Processes in which the compositions first dissolve in water before being added to the suspension or to the soil are also preferred, since they are processes in which water-soluble cationic polymers are precipitated as a dispersion, optionally in the presence of a second water soluble polymer.

Surprisingly, it has also been found that mixtures of anionic organic salts and cosmotropic salts are useful for precipitating cationic water soluble polymers. The embodiments of this invention include compositions composed of water, at least one precipitated cationic water-soluble polymer, an effective amount of at least one cosmotropic salt, and an effective amount of at least one anionic organic salt; Preferred embodiments include compositions composed of water, at least one polymer soluble in precipitated cationic water, from 1% to 27% by weight, based on the total weight, of a sulfate salt, and from 0.5% to 35% by weight , based on the total weight, of a sulfonate salt, wherein the precipitated cationic water-soluble polymer is composed of recurring units of a quaternary salt of a dialkylaminoalkyl (alk) acrylate. Also preferred are compositions, optionally containing a second water soluble polymer, in which the cationic water soluble polymer is precipitated as a dispersion.

Other embodiments include processes comprising mixing, in any order, water, at least one cationic water soluble polymer, an effective amount of at least one cosmotropic salt, and an effective amount of at least one anionic organic salt, to form a composition aqueous comprising at least one precipitated cationic water-soluble polymer; Preferred embodiments include the processes comprising mixing, in any order, a cationic water-soluble polymer composed of recurring units of a quaternary salt of a dialkylaminoalkyl (alk) acrylate, from 0.5% to 35%, by weight based on total weight , of a sulfonate salt, and from 1% to 27%, by weight based on the total weight, of a sulfate salt, to form an aqueous composition comprising at least one precipitated cationic water-soluble polymer. Also preferred are processes which comprise mixing in a second water-soluble polymer.

Additional embodiments include processes comprising the polymerization of at least one cationic monomer in an aqueous solution composed of an effective amount of at least one anionic organic salt and an effective amount of at least one cosmotropic salt, to form an aqueous composition comprising at least one precipitated cationic water soluble polymer; Preferred embodiments include processes comprising the polymerization of monomers composed of a quaternary salt of a dialkylaminoalkyl (alk) acrylate, in an aqueous solution composed of (a) from 0.5% to 40%, by weight based on total weight, a sulfonate salt and (b) from 1% to 28%, by weight based on the total weight, of a sulfate salt, to form an aqueous composition comprising at least one precipitated cationic water-soluble polymer. Processes are preferred in which water-soluble cationic polymers are precipitated as a dispersion, optionally in the presence of a second water-soluble polymer.

The applications of the present invention include the processes of concentrating a dispersion of suspended solids, which comprise the dewatering of a dispersion of suspended solids by adding to the dispersion an effective amount of an aqueous composition composed of an effective amount of at least one salt anionic organic, an effective amount of at least one cosmotropic salt, and at least one polymer soluble in precipitated cationic water, and separation of the resulting concentrated dispersion; Preferred embodiments include the processes of concentrating a dispersion of suspended solids, which comprise the dewatering of a biologically treated suspension by adding to the suspension an effective amount of a composition composed of from 1% to 27% by weight, based on the weight total, of a sulfate salt, and from 0.5% to 35% by weight, based on the total weight, of a sulfonate salt, and at least one precipitated cationic water soluble polymer, and separation of the resulting concentrated dispersion, wherein the precipitated cationic water soluble polymer is composed of recurring units of a salt quaternary of a dialkylaminoalkyl (alk) acrylate. Other applications include soil conditioning processes, which comprise adding to the soil an amount for soil conditioning an aqueous composition composed of an effective amount of at least one anionic organic salt, an effective amount of at least one cosmotropic salt, and at least one precipitated cationic water soluble polymer. Processes in which the compositions first dissolve in water before being added to the suspension or to the soil are also preferred, since they are processes in which water-soluble cationic polymers are precipitated as a dispersion, optionally in the presence of a second water soluble polymer.

Brief Description of the Drawings The following abbreviations are used in the drawings and in the entire specification: Poly (DMAEM.BzCl): Poly (methacryloxyethyldimethylbenzylammonium chloride) Poly (DEAEM.MeCl): Poly (methacryloxyethyldiethylmethylammonium chloride) Poly (AMBTAC): Poly (acrylamido (2-methylbutyl) trimethylammonium chloride) Poly (DMAEM.MeCl): Poly (methacryloxyethyltrimethylammonium chloride) Poly (DMAEA.MeCl): Poly (acryloxyethyltrimethylammonium chloride) P? Li (MAPTAC): Poly (acrylamidopropyltrimethylammonium chloride) The attached drawings are presented in conjunction with the Detailed Description below: Figure 1 is a plot of the cloudiness temperatures of poly (DMAEM.MeCl) at 0.5% by weight as a function of% by weight of NaSCN and% by weight of (NH) 2S0.

Figure 2 is a graph of the cloudiness temperatures of poly (DMAEM.MeCl) at 5% by weight as a function of% by weight of NaSCN and the type of cosmotropic salt.

Figure 3 is a plot of the cloudiness temperatures of the poly (DMAEM.MeCl) at 0.5% by weight as a function of the chaotropic salt concentration in (NH4) 2S04 at 20% by weight.

Figure 4 is a plot of the cloudiness temperatures of six cationic polymers at 0.5% by weight as a function of the concentration of NaSCN in 5% (NH4) 2S0 by weight.

Figure 5 is a plot of the cloudiness temperatures of poly (DMAEM.MeCl) at 0.5% by weight and poly (acrylamide / DMAEM.MeCl / ethyl acetate) (45/45/10 mole percent) as a function of NaSCN concentration in 5% (NH4) 2S04 by weight.

Figure 6 (a) and 6 (b) are graphs of the cloudiness temperatures of poly (DMAEM, MeCl) and poly (DMAEM, DMS) (the polymer of the dimethyl sulfate quaternary salt of DMAEM), respectively, as a function of the concentration of NaSCN in 5% (NH4) 2S04 by weight.

Figure 7 is a plot of the cloudiness temperatures of poly (DMAEM.MeCl) at 0.5% by weight as a function of% by weight of Nal in a mixture of Nal / NaBr at 4% by weight in (NH4) 2S04 at 20% by weight. The straight line that connects the end points of the curved line is the expected behavior based on the "mix rule".

Figure 8 is a plot of the cloudiness temperatures of poly (DMAEM.MeCl) at 0.5% by weight as a function of the anionic organic salt concentration in the absence of (NH4) 2S0. (Comparative).

Figure 9 is a plot of the cloudiness temperatures of the poly (DMAEM.MeCl) at 0.5% by weight as a function of the concentration of anionic organic salt in (NH4) 2S04 at 20% by weight.

Figure 10 is a plot of the cloudiness temperatures of poly (45-AMD / 55-DMAEM.MeCl) (a copolymer having 45 mol% acrylamide and 55 mol% DMAEM.MeCl) as a function of% by weight of DIBSS (sodium diisobutylsulfosuccinate) in 5% (NH4) 2S04 by weight and 15% (NH4) 2S04 by weight.

Figure 11 is a graph of 10-second free drainage of flocculated mud (suspended solids from a biologically treated suspension) as a function of the polymer dose, where the dose is expressed in units of polymer pounds per dry ton of solids of mud. The "precipitated polymer" is a composition formed by the process of Example 20, and the "polymer in solution" is a composition formed by the process of Example R.

Detailed Description of the Preferred Modalities Surprisingly, it has been discovered that the precipitation of water-soluble cationic polymers by chaotropic salts, or anionic organic salts, is increased by the addition of cosmotropic salts. This is surprising because the effects of the salts are generally considered to be additive. The effects of the salt are additive, it should be expected that the solubility effects of a chaotropic salt, for example, sodium thiocyanate, of a particular substance in water should be combated or eliminated by the effects of a strongly strongly cosmotropic salt, such like (NH4) 2S04. Quite the contrary, it has now been found that these effects tend to be synergistic, so that the cationic water-soluble polymers are more effectively precipitated by a combination of chaotropic and cosmotropic salts than by either a single salt.

For the purposes of this invention, a polymer is precipitated in a particular salt solution if the particular polymer does not dissolve to form a homogeneous, clear solution when the particular polymer is shaken or agitated, for periods of up to about a week, in the salt solution at a particular temperature. Also a polymer is considered to be precipitated when a solution of a polymer or polymers in the salt solution develops turbidity or turbidity, when the temperature of the solution is changed. It is obvious from the above that the solubility of a polymer or polymers in a particular salt solution can be temperature dependent, so that a polymer can be precipitated in a particular salt solution at low temperatures, but dissolves at temperatures high, or vice versa. The polymer or polymers, salt or salts, and water can be mixed in any order, or the polymerization can be carried out in the presence of the salts, or part of the salts, to determine the solubility of the polymer in the salt solution. . The polymer can be considered to be precipitated if all or only part, for example, 10% or more, of the polymer is precipitated.

Those skilled in the art understand that the solubility of water-soluble, cationic polymers is often determined by measuring the clouding temperature of the polymer in the salt solution. The clouding temperature of a particular polymer in a particular salt solution is defined, for the purposes of this invention, as the temperature at which a substantially clear solution of the polymer becomes cloudy since it cools. For example, a composition composed of at least one cationic polymer, soluble in water, water, and the salt mixture can be heated to dissolve the polymer, forming a substantially clear solution. Then the solution can be allowed to cool slowly, until the polymer begins to precipitate or the phase separates and the solution becomes turbid or turbid. The temperature at which the solution begins to become cloudy is the cloudiness temperature. The reproducibility of the cloudiness temperatures determined in this way is generally about ± 3 ° C. The polymers which are less soluble have higher cloud temperatures, and the polymers which are more soluble have lower haze temperatures. In some cases, the cloudiness temperatures are difficult to measure conveniently, because the polymers are thus insoluble since they are solubilized with heating, even by heating to about 100 CC or higher. At ambient pressure, 100 ° C is close to the boiling point of the aqueous solution, so that measurements at higher temperatures are not practical. Likewise, some polymers are thus insoluble since they do not precipitate, even with cooling below about 0 ° C, which is the practical limit for measurements of cloudiness due to freezing.

Occasionally, a situation is found in which a polymer precipitates from the salt solution with heating, rather than with cooling. In these cases, the clouding temperature of a particular polymer in a particular salt solution, for the purposes of this invention, is defined as the temperature at which a solution of the polymer begins to become cloudy since it is heated. Then, all the cloudiness temperatures are obtained with cooling, except for the opposite observation.

The polymerization of the monomers can be carried out in the presence of the salt mixture. For example, the amounts of water, monomers and salts can be mixed together and subjected to polymerization conditions. Then the cloudiness temperatures can be determined as mentioned above. The polymerization of the monomers in the presence of the salts may be preferable, particularly at a high polymer concentration or a high molecular weight of the polymer, because of the difficulty of adequately mixing the polymer with the salt solution. This technique may also be preferable when the clouding temperature is ger than 100 ° C.

The effective amounts of the chaotropic salt, or anionic organic salt, and the actual amounts of cosmotropic salt required to cause the precipitation or phase separation of the cationic water soluble polymers depends on a number of factors, including temperature, inherent solubility. of the polymer, the concentration of the polymer, the particular chaotropic salt, or anionic organic salt, used, and the particular cormotropic salt used. The amount of chaotropic salt, or anionic organic salt, also depends on the amount of cosmotropic salt. For example, Table 1 shows the cloudiness temperatures of poly (DMAEM.MeCl) at 0.5% as a function of the concentration of sodium thiocyanate and the concentration of (NH4) 2S0 where the concentrations are expressed as percent by weight of the total weight. Then, all concentrations, unless otherwise noted, are expressed as percent by weight of the total weight. The data in Table 1 is plotted in Figure 1. For each curve in Figure 1, it is observed that the poly (DMAEM, MeCl) is insoluble at temperatures below the curve and soluble at temperatures above the curve. . At NaSCN concentrations below 1%, the poly (DMAEM, MeCl) is not precipitated, even at about 10% (NH4) 2S04.

Table 1. 0.5% Poly (DMAEM.MeCl) clouding temperatures as a function of% by weight of NaSCN and% by weight of (NH4) 2S04.

To achieve a particular degree of polymer insolubility for a particular water-soluble polymer, Table 1 (Figure 1) shows that one can manipulate the amount of chaotropic salt, or anionic organic salt, the amount of cosmotropic salt, the temperature, or some combination of them. Without (NH4) 2S04, the cloudiness temperatures of the poly (DMAEM, MeCl) reach a maximum of about 30 ° C at a NaSCN concentration of about 4%. At this point, the additional addition of chaotropic NaSCN increases the solubility of the polymer, since it decreases the cloudiness temperature. In this case, there is an effective amount of sodium thiocyanate ranging from about 3% to about 5%, which causes the precipitation of the polymer at room temperature. It is clear to one skilled in the art that the range can be extended by reducing the temperature, or by increasing the concentration of (NH4) 2S0.

The data in Tables 2 and 3 show that the particular type of cosmotropic salt and the particular type of chaotropic salt, respectively, can also influence the clouding temperatures of the poly (DMAEM.MeCl). The data in Tables 2 and 3 are plotted in Figures 2 and 3, respectively. For this particular polymer at this particular concentration, Figure 2 shows that, for equal amounts by weight, Na2SO4 tends to give higher cloudiness temperatures than it (NH4) 2S0. In turn, it (NH4) 2S04 tends to give higher turbidity temperatures than Al2 (S04) 3 »18H20, even when larger amounts, by weight, of Al2 (S04) 3 * 18H20 are used, depending on the NaSCN concentration. The clouding temperatures of the poly (DMAEM.MeCl) in the absence of cosmotropic salt are shown by comparison. Figure 3 shows that some chaotropic salts are more effective than others, and that the order of efficacy is roughly opposite to the expected order based on the Hofmeister series; for example, the most effective salts to insolubilize the poly (DMAEM.MeCl) tend to be the more strongly chaotropic salts, while the less effective salts tend to be less strongly chaotropic. Observe the effectiveness of sodium benzenesulfonate (NaS03Ph), an organic anionic salt which will be discussed below.

Table 2. Poly (5% DMAEM.MeCl) Turbidity Temperatures as a Function of NaSCN Concentration and Cosmotropic Salt Type Table 3. Poly turbidity temperatures (DMAEM.MeCI) as a function of the concentration of NaX in (NH4) 2S? 4. tom Table 4, plotted in Figure 4, shows the cloudiness temperatures of the 0.5% solutions of various water-soluble cationic polymers as a function of the concentration of NaSCN in the 5% (NH4) 2S04 solution. Even though these polymers are highly water soluble and non-hydrophobic per se, some of the polymers can be considered more hydrophobic than others because they have a higher content of hydrophobic groups. In general, polymers which are more hydrophobic tend to have higher clouding temperatures for a given combination of chaotropic salt, or anionic organic salt, and cosmotropic salt. For example, Figure 4 shows that the clouding temperatures of poly (DMAEM, BzCl), which contains hydrophobic benzyl groups, are completely high, even at very low NaSCN concentrations. At higher NaSCN concentrations, the cloudiness temperatures are not determined because the poly (DMAEM, BzCl) does not dissolve, even at 100 ° C. At the other extreme, less hydrophobic polymers, such as poly (DMAEA.MeCl) and poly (MAPTAC) have much lower cloud temperatures. Polymers with intermediate hydrophobicity, such as poly (DMAEM, MeCl) and poly (AMBTAC), have cloud temperatures that are intermediate between poly (DMAEM, BzCl) and poly (DMAEA.MeCl). The cationic copolymers and terpolymers can also be precipitated using the compositions and processes of this invention. For example, Table 5 (plotted in Figure 5) shows the cloudiness temperatures of the poly (DMAEA.MeCl) and a terpolymer of AMD / DMAEA.MeCl / EA (obtained by polymerizing 45% molar acrylamide (AMD), 45% molar DMAEA.MeCl and 10% molar ethyl acrylate (EA) mole in 5% (NH4) 2S04 as a function of the NaSCN concentration.

Table 4. 0.5% Caustic Polymer Turbidity Temperatures as a Function of NaSCN Concentration in (Nr-U) 2S? 4.

Table 5. Turbidity Temperatures of Poly (AMD / DMAEA.MeCl / EA) (45/45/10 mol) and Poly (DMAEA.MeCl) in 5% (NH4) 2S04 as a NaSCN Concentration Function.

Table 6 (Figure 6) shows the cloudiness temperatures of two polymers as a function of polymer concentration (0.5%, 5%, 15%, and 20%) and the concentration of NaSCN in 5% (NH4) 2S0. . These data show that the cloudiness temperatures can also be affected by the concentration and counter-ion of the cationic polymer. Figure 6 (a) shows the cloudiness temperatures of poly (DMAEM, MeCl) as a function of the concentration of NaSCN in 5% (NH4) 2S04. Poly (DMAEM, MeCl) is the polymer obtained by polymerizing the quaternary dimethylaminoethyl methacrylate salt of methyl chloride. Since the concentration of the polymer increases, the amount of NaSCN needed to produce a particular clouding temperature also tends to increase. Figure 6 (b) shows the cloudiness temperatures of the poly (DMAEM, DMS), which is the polymer obtained by polymerizing the quaternary dimethylaminoethylmethacrylate salt of dimethyl sulfate. Note that the change in the amount of NaSCN required to give a certain cloudiness is different for the two polymers, which are substantially the same, except for their counterion identity.

Table 6. Poly Blotting Temperatures (DMAEM.MeCI) and Poly (DMAEM.DMS) as a Function of NaSCN Concentration in 5% (NH4) 2S? 4 and Various Concentrations of Polymer CJ Vo The effective amounts of the anionic organic salt, which will insolubilize a particular cationic water-soluble polymer, in the presence of cosmotropic salt, are generally in the range of from about 0.1% to about 40%, preferably from about 0.5% to about 35%, more preferably from about 1% to about 30%. In the case of chaotropic salts, the effective amounts of chaotropic salt which will insolubilize a particular cationic water soluble polymer, in the presence of cosmotropic salt, are generally in the range of about 0.5% up to about 250%, preferably in the range of about 1% up to about 200%, more preferably in the range of about 7% to about 150%, more preferably in the range of about 10% to about 100%, by weight, based on the weight of the polymer. The effective amounts of cosmotropic salt useful in the mixture with the anionic organic salt and / or the chaotropic salt are in the range of about 0.1% to about 30%, preferably from about 1% to about 27%, more preferably from about 10% to about 25%. Preferably, the salts are soluble in the solution, so that the upper limits for the salt content are determined primarily by the ability of the solution to dissolve the salt, which is, in turn, affected by temperature and the amount of the polymer in the composition. The effective amounts of chaotropic salt, or anionic organic salt, and the effective amounts of cosmotropic salt useful for precipitating a particular polymer at a particular temperature can be found by routine experimentation, following the trends established in the results discussed herein.

When a polymerization of monomers is carried out in the presence of chaotropic salt or anionic organic salt, and cosmotropic salt, the effective amounts of anionic organic salt which will insolubilize the resulting cationic water-soluble polymer, in the presence of cosmotropic salt, generally they are in the range from about 0.2% to about 50%, preferably from about 0.5% to about 40%, more preferably from about 1% to about 35%, more preferably from about 5% to about 25% . In the case of chaotropic salts, the effective amounts of chaotropic salt which will insolubilize the resulting cationic water-soluble polymer, in the presence of cosmotropic salt, are generally in the range of from about 0.1% to about 250%, preferably in the the range of about 2% to about 220%, more preferably in the range of about 8% to about 150%, more preferably in the range of about 10% to about 100%, by weight, based on weight of the monomers. The effective amounts of cosmotropic salt useful in the mixture with the anionic organic salt and / or the chaotropic salt are in the range of from about 0.5% to about 30%, preferably from about 1% to about 28%, more preferably from about 5% to about 25%. Preferably, the salts are soluble at the end of the polymerization, so that the upper limits for the salt content are mainly determined by the ability of the solution to dissolve the salt, which is, in turn, affected by the temperature and the amount of polymer in the composition. The effective amounts of chaotropic salt, or anionic organic salt, and the effective amounts of cosmotropic salt useful when carrying out a polymerization of monomers at a particular temperature can be found by routine experimentation, following the trends established in the results discussed herein.

The chaotropic salts useful in this invention may be any chaotropic salt which includes the thiocyanates, perchlorates, chlorates, bromates, bromides, iodides and nitrates. The anion counterion has a relatively small effect on the solubility of the cationic polymer, and can be ammonium or any alkali metal cation, such as lithium, sodium or potassium, or an alkaline earth metal cation. Sodium thiocyanate, potassium thiocyanate, ammonium thiocyanate, sodium perchlorate, sodium chlorate, sodium bromide, sodium iodide and sodium nitrate are preferred. Mixtures of chaotropic salts are useful, and may provide a benefit when used with the cosmotropic salt. For example, Table 7 (Figure 7) shows the cloudiness temperatures of the 0.5% poly (DMAEM, MeCl) as a function of the amount of Nal in a mixture of Nal and NaBr, in 20% (NH4) 2S04. The total weight of chaotropic salt, Nal + NaBr, remains constant at 4% of the total weight. In this case, the cloudiness temperatures do not follow the simple behavior of the "mixing rule" that should be expected if each chaotropic salt influences the cloudiness in proportion to its weight fraction in the solution; that is, the turbidity temperature curve is not linear as a function of the amount of Nal in the mixture, and instead shows that the cloudiness temperatures, which are advantageously greater than those that should be expected based on the "rule" of mixtures "can be obtained using a mixture of chaotropic salts.

Table 7. Poly Blotting Temperatures (DMAEM, MeCl) at 0.5% in 20% (NH4) 2S04 and 4% Nal / NaBr Mixture as a Function of the Fraction Weight of Nal in the Mixture.

The cosmotropic salts useful in the present invention can be any cosmotropic salt that includes sulphates, phosphates, fluorides, citrates, acetates, tartrates, and hydrogen phosphates. The counterion has a small effect on the solubility of the polymer as shown in Table 2 (Figure 2), and can be ammonium or any alkaline or alkaline earth metal, such as lithium, sodium, potassium, magnesium, calcium, etc. The counterion can also be aluminum, as shown in Table 2 (Figure 2), or it can be a transition metal cation, such as manganese or iron. The preferred cosmotropic salts are ammonium sulfate and sodium sulfate. Mixtures of cosmotropic salts are also effective and may be preferred.

It has also been found that organic anionic salts, such as anionic hydrotropic salts and anionic surfactants, also precipitate cationic polymers, when used in conjunction with cosmotropic salts. Organic anionic salts with the general structure RA "M +, wherein R comprises ester, alkylenoxy, alkyl, or alkyl substituted with from about 1 to about 22 carbons, or aryl or aryl substituted with from about 6 to about 22 carbons, A is a Anionic group, such as the carboxylate, sulfonate, or sulfate group, and M is a metal or ammonium, are useful for the precipitation of cationic polymers, in the presence of cosmotropic salts, The R group can be linear or branched, and can be substituted with more than one anionic group A. The anionic group A can be substituted with more than one group R. The mixtures of anionic organic salts with each other, or with chaotropic salts, are also useful, in the mixture with a salt or cosmotropic salts The exceptions to this are acetate, citrate and tartrate anions, which tend to be cosmotropic.

Preferred anionic organic salts contain anions, such as trichloroacetate and trifluoromethanesulfonate; also sulfonates and disulfonates, such as methanesulfonate, ethanesulfonate, propanesulfonate, butanesulfonate, butanedisulfonate, pentanesulfonate, hexanesulfonate, hexanedisulfonate, and octanedisulfonate; also sulfonates and disulfonates of aryl or substituted aryl, such as benzenesulfonate, nitrobenzenesulfonate, xylene sulfonate, toluenesulfonate, benzenedisulfonate, naphthalenesulfonate, etc. and the resemblance. Other preferred organic salts contain anions, such as dialkylsulfosuccinate, dicycloalkylsulfosuccinate, diarylsulfosuccinate, diisobutylsulfosuccinate, diisooctylsulfosuccinate, dimethylsulfosuccinate, diethylsulfosuccinate, and diisopropylsulfosuccinate. Sodium hexanesulfonate, sodium benzenesulfonate, and sodium xylene sulfonate are more preferred. Most preferred are sodium benzenedisulfonate, sodium butane-disulfonate, sodium hexanedisulfonate, sodium octane disulfonate, and sodium decanedisulfonate.

Tables 8 and 9 (Figures 8 and 9, respectively) show the cloudiness temperatures of poly (DMAEM.MeCl) as a function of anionic organic salt concentration, without (NH4) 2S04 (Table 8 and Figure 8) and with about 20% of (NH4) 2S04 (Table 9 and Figure 9). Table 8 (Figure 8) shows that, at concentrations of up to about 5 anionic organic salts, naphthalenesulfonates, xylenesulfonate and nitrobenzenesulfonate cause precipitation of 0.5% poly (DMAEM.MeCl) in the absence of (NH4) 2S04. The efficacy of the anionic organic salts also increases, as evidenced by the increase in cloud points, by the presence of 20% (NH4) 2S04 (Table 9 and Figure 9). Table 9 and Figure 9 also demonstrate the ease of two organic anionic salts, sodium trichloroacetate and sodium benzenesulfonate, to precipitate the poly (DMAEM.MeCl) in the presence of (NH4) 2S04.

Table 8. 0.5% Poly (DMAEM.MeCI) Turbidity Temperatures as a Function of the Anionic Organic Salt Concentration, Sin (NH4) 2S04.

Table 9. Poly-Turbidity Temperature (DMAEM.MeCI) at 0.5% as a Function of the Concentration of Organic Anionic Salt, (Nr-U) 2S? 4.

Table 10 (Figure 10) shows the cloudiness temperatures of a copolymer composed of 45 mol% acrylamide and 55 mol% poly (DMAEA.MeCl) as a function of the concentration of DIBSS and (NH) 2S04. The concentration of the copolymer, abbreviated as poly (45-AMD / 55-DMAEA.MeCl), is 0.5%. Note that increasing the concentration of (NH4) 2S04 from 5% to 15% decreases the amount of DIBSS useful to insolubilize the polymer.

Table 10. Pollution Temperatures of the Poly (45-AMD / 55-DMAEM.MeCl) at 0.5% as a Function of the% by Weight of DIBSS at Different Levels of (NH4) 2S04.

The effective amounts of cosmotropic salt and anionic organic salt, including anionic hydrotropic salts and anionic surfactants, useful for causing precipitation or phase separation depend on the temperature, the inherent solubility of the polymer, the concentration of the polymer, the anionic organic salt particular used, and the particular cosmotropic salt used. The effective amount of anionic organic salt also depends on the amount of cosmotropic salt. When used without a cosmotropic salt, a larger amount of anionic organic salt is generally necessary to produce a particular level of polymer insolubility than when a cosmotropic salt is present. The effective amounts of anionic organic salt and the effective amounts of cosmotropic salt useful for precipitating a particular polymer at a particular temperature can be found by routine experimentation, following the trends established in the results discussed herein.

The polymers used in the practice of this invention can be any water-soluble cationic polymer, including polymers made by the polymerization and copolymerization of cationic monomers, and the polymers which become cationically changed after the polymerization has been presented. . The% mole of cationic recurring units, based on the total moles of recurring units in the polymer, is generally from about 1 mole% to about 100 mole%, preferably from about 10 mole% to about 90% mol, more preferably preferable from about 20 mol% to about 80 mol%, more preferably from about 30 mol% to about 70 mol%. The polymers useful in this invention may include those having recurring units represented by the following general formula (I): where R, is either hydrogen or CH3, A is either an oxygen atom or NH, R2 and R3 are each, individually, an alkyl group having from about 1 to about 3 carbons, B is an alkylene group or oxyalkylene having 1 to 5 carbons, R 4 is an alkyl group or a substituted alkyl group having from about 1 to about 10 carbons, or a substituted aryl or aryl group having from about 6 to about 10 carbons, and X is an anionic counterion. Preferably, A is an oxygen atom, B has two carbons, R2 and R3 are methyl or ethyl, and j is methyl, ethyl, or benzyl. Preferably, the cationic polymers are prepared from, or contain recurring units corresponding to quaternary dialkylaminoalkyl (alk) acrylate salts, including methyl chloride, dimethyl sulfate, alkyl halide, and quaternary benzyl chloride salts of such monomers such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, etc. and the resemblance. Other cationic polymers and copolymers, such as poly (diallyldialkyl ammonium halide), polyamines, and condensation polymers made from monomers, such as epichlorohydrin and dimethylamine are also useful in the practice of this invention.

The monomers which can be copolymerized with the cationic monomers mentioned above can be cationic, nonionic or anionic. The cationic monomers include the monomers corresponding to (I) and other cationic monomers, such as diallydimethylammonium chloride, dialidiethyl ammonium chloride, etc. Nonionic monomers can include substantially water-soluble monomers, such as acrylamide, methacrylamide, and N-isopropylacrylamide, or monomers which are poorly water soluble, such as t-butylacrylamide, N, N-dialkylacrylamide, acrylamide diacetone, ethyl acrylate, methyl methacrylate, methyl acrylate, styrene, butadiene, ethyl methacrylate, acrylonitrile, etc. and the like. Nonionic monomers may also include monomers which become charged at low pH, such as dimethylaminoethylacrylate, dimethylaminoethylmethacrylate, diethylaminoethylacrylate, diethylaminoethyl methacrylate and corresponding acrylamide derivatives, such as methacrylamidopropyldimethylamine. Preferred nonionic monomers are acrylamide, t-butyl acrylamide, methacrylamide, methyl methacrylate, ethyl acrylate and styrene. The anionic monomers can include acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, their salts and the like. In a mol base, the polymer contains few anionic recurring units than the cationic recurring units, so that the polymer, although ampholytic, retains a net positive cationic charge. Preferably, the polymer contains less than 10 mol% of anionic recurring units, based on the total number of recurring units in the polymer.

The polymers which become cationically charged, for example by quaternization, after polymerization include the homopolymers produced from such monomers as dimethylaminoethylacrylate, dimethylaminoethyl methacrylate, diethylaminoethylacrylate, diethylaminoethyl methacrylate and corresponding acrylamide derivatives, such as methacrylamidopropyldimethylamine, as well as the copolymers with any of the other monomers discussed above. Functionalized acrylamide polymers, such as those glyoxylated or mannich polymers produced in Patentse U.S. 5,132,023; 5,037,881; 4,956,399; 4,956,400; which are incorporated herein by reference, are also useful in the practice of this invention.

The present invention is more useful for precipitating polymers such as poly (DMAEM, MeCl), which does not contain hydrophobic groups, for example, benzyl groups which make it easier to precipitate the polymer, because such polymers can be difficult or impossible to precipitate using a single cosmotropic salt. However, mixtures of chaotropic salt, or anionic organic salt, and cosmotropic salt can also be used to precipitate the polymers, which can be precipitated in a single cosmotropic salt. The use of a salt mixture, for example, chaotropic with cosmotropic can provide a benefit over the use of a single cosmotropic salt, because the salt mixture can precipitate the polymer more effectively, for example, the clouding temperature can be higher, the total salt level may be lower, the apparent viscosity may be lower, for example, from a polymer dispersion, etc.

For example, a 1% solution of a terpolymer prepared by polymerizing 20% DMAEA.MeCl mole, 20% DMAEA.BzCl mole (benzyl chloride quaternary dimethylaminoethylacrylate salt), and 60% molar AMD can be precipitated in a solution containing 30% ammonium sulfate, but can be soluble in a solution containing 25% ammonium sulfate. From a practical point of view, it can be disadvantageous to use salt levels in excess of 25% to precipitate the polymer. However, the total salt content can be drastically decreased by using a mixture of a chaotropic salt and a cosmotropic salt. For example, a 1% solution of the same terpolymer can be precipitated in a solution containing 10% ammonium sulfate and 0.75% NaSCN, a total salt level of only 10.75%, against a total salt level of about 30. % for ammonium sulfate only.

Mixtures of one or more polymers can be precipitated by the practice of this invention. The polymers can be mixed together before, during or after being mixed with part or all of the salt solution. The polymer blends can be separated from each other using a salt solution which tends to precipitate one or more polymers in the mixture, but is a solvent for one or more different polymers in the mixture. Additional salts may be added before, during or after the precipitation process. A polymer or copolymer can also be formed by polymerizing the monomers in the presence of another polymer or polymers, which themselves can be precipitated or soluble in the salt solution.

The polymerization of the monomers can be carried out in any manner known to those skilled in the art, including solution, mass, precipitation, dispersion, suspension, emulsion, microemulsion, etc. The polymerization of the monomers can be carried out in the presence of part or all of the salt solution. Initiation can be effected with a variety of redox free radical and thermal initiators, including peroxides, for example, t-butyl peroxide; azo compounds, for example, azoisobisbutyronitrile; inorganic compounds, such as potassium persulfate and redox pairs, such as ferrous ammonium sulfate / ammonium persulfate and sodium bromate / sulfur dioxide. The addition of the initiator can be carried out at any time before the initial initiation per se. Polymerization can also be carried out by photochemical irradiation processes, such as by ultraviolet irradiation or by ionizing irradiation of a cobalt source 60. All monomers may be present when the polymerization is initiated, or part of the monomers may be added to a previous stage of the polymerization. The polymerization can be carried out in multiple stages. Additional materials such as pH adjusting agents, stabilizers, chelating agents, sequestering agents, etc. They can also be added before, during or after polymerization The molecular weights of the polymers which are precipitated or phase separated by the practice of this invention are not particularly critical. The average molecular weights of the polymers can range from about 1,000 to about 100,000,000, preferably from about 100,000 to about 75,000,000, more preferably from about 1,000,000 to about 60,000,000. The concentration of the polymer in the composition can range from 0.01% to 90%, or occasionally even higher. It is generally preferred, for practical reasons, such as the desire to keep production and transport costs relatively low, that the level of polymer in the compositions be as high as possible.

The compositions of the salt solutions, useful for precipitating the cationic polymers, can be prepared by simply dissolving the desired salts in water, preferably with stirring. The waters useful in the practice of this invention are not particularly critical and can be from any water source, eg, distilled water, tap water, recycled water, process water, well water, etc. The precipitation of the cationic polymer in the salt solution can be carried out by mixing, in any order, the salt solution and the polymer solution or polymer emulsion. A different second water-soluble polymer can be mixed to stabilize the droplets of precipitated polymer by retarding or preventing settling. The dried polymer granules substantially of water soluble polymer can be added to the salt solutions to form the compositions comprising salts, water and precipitated polymer. Alternatively, the cationic water-soluble polymer can be formed by polymerizing the monomers in the presence of the salts. It can precipitate all or part of the polymer.

It is preferred to polymerize the monomers in a salt solution to form a polymer dispersion. For the purposes of this invention, the precipitated polymer is a polymer dispersion if part or all of the precipitated polymer is in the form of small droplets that are dispersed in the aqueous salt solution. Droplets of precipitated polymer may contain salt and water. A part or all of the polymer can be precipitated. The size of the droplet may be in the range from about 0.1 microns to about 1 millimeter, preferably from about 0.1 microns to about 100 microns, more preferably from about 0.1 microns to about 10 microns, and more preferably from about 10 microns. approximately 0.1 microns to approximately 5 microns. As mentioned above, the monomer or monomers and the salt or salts can be added in stages during the polymerization or all is presented at the beginning. The initiation of the polymerization is carried out in any way, as described above.

The dispersed polymer droplets may tend to settle at rest. Surprisingly, it has been found that certain water-soluble polymers, which can be referred to herein as dispersants, tend to stabilize the droplets against settling. The polymer dispersant stabilizes the polymer dispersion, but does not cause the polymer soluble in cationic water to precipitate. As discussed above, the salt combination causes the soluble polymer to precipitate cationic water. It has been found that polymers such as polyacrylamide and acrylamide copolymers with amounts of cationic, nonionic and anionic monomers decrease the rate of sedimentation of the dispersions. For example, the polymerization of a mixture of 45% molar acrylamide and 55% molar DMAEA.MeCl in the presence of about 6% sodium benzenedisulfonate and about 15% (NH4) 2S04 gives a polymer dispersion containing the precipitated copolymer of acrylamide and DMAEA.MeCl. The polymer droplets tend to settle over time and can be joined to form a layer that separates from the aqueous phase. However, when the same polymerization is carried out in the presence of another water-soluble polymer, for example, polyacrylamide, or acrylamide copolymers with cationic, anionic or non-ionic monomers, the proportion of sedimentation is drastically reduced.

The water soluble polymer, which can act as a dispersant, can be mixed before, during or after mixing together the cationic water-soluble polymer, water and salts. Preferably, the polymerization of the monomers in the presence of chaotropic salt, or anionic organic salt, and cosmotropic salt to form a precipitated water-soluble cationic polymer is carried out in the presence of one or more water-soluble polymers other than the polymer soluble in cationic water.

Polymers useful as dispersants may include polyacrylamide and other non-ionic polymers, for example, poly (methacrylamide), poly (vinyl alcohol), poly (ethylene oxide), etc. and the like. Generally, the dispersants are soluble or mainly soluble in the particular salt solution. It is generally preferable for the dispersant to have greater solubility in the particular salt solution than the droplets of precipitated polymer, which are being dispersed. Cationic polymers, for example, poly (MAPTAC), poly (DMAEA.MeCl), etc. and the like are useful as dispersants when the polymer that precipitates is less soluble than the dispersant. Copolymers useful as dispersants can include copolymers of nonionic monomers, for example, acrylamide with up to about 99 mol%, preferably up to about 50 mol%, more preferably from about 5 to about 25 mol%, based on the total moles of recurring units in the polymer, of cationic comonomers, for example, DMAEA.MeCl, DMAEM. MeCl, diallydimethylammonium chloride, etc. Other copolymers useful as dispersants include copolymers of acrylamide with up to about 30 mol% of an anionic comonomer, such as 2-acrylamido-2-methylpropanesulfonic acid sodium, preferably from about 5 to about 20% comonomer, based on the total moles of recurring units in the polymer. Anionic comonomers may include acrylic acid, styrenesulfonic acid, its salts and the like. The nonionic comonomers may include substantially water-soluble monomers, such as methacrylamide, or monomers which are sparingly soluble in water, such as t-butylacrylamide, diacetone acrylamide, ethyl acrylate, methyl methacrylate, methyl acrylate. , styrene, butadiene, ethyl methacrylate, acrylonitrile, etc., and the like. The nonionic comonomers may also include the monomers which become charged at low pH, such as the dimethylaminoethylacrylate, dimethylaminoethyl methacrylate, diethylaminoethylacrylate, diethylaminoethylacrylate and corresponding acrylamide derivatives, such as methacrylamidopropyldimethylamine. The non-ionic comonomers are acrylamide, t-butyl acrylamide, methacrylamide, methyl methacrylate, ethyl acrylate and styrene.

Dispersants which have a graft or block structure are particularly preferred. For example, those skilled in the art realize that copolymers prepared by polymerizing acrylamide in the presence of polyvinyl alcohol, using certain initiators, for example, (NH4) 2Ce (N03) 6, result in graft copolymers. or block. The polyvinyl alcohol may constitute up to about 50% of the weight of the copolymer, preferably from about 5% to about 30%.

Dispersants are generally used in amounts ranging up to about 25%, preferably about 1% to about 20%, more preferably about 5% to about 15%, based on the total weight of precipitated cationic polymer droplets that they scatter. The dispersant is not used in amounts which cause precipitation of the cationic polymer in the absence of chaotropic salts, or anionic organic salts, and cosmotropic salts. The weight average molecular weights of the dispersant polymers can range from about 1,000 to about 50,000,000, preferably from about 50,000 to about 10,000,000, preferably from about 100,000 to about 5,000,000.

Routine experimentation used to identify an effective combination of chaotropic salt or anionic organic salt, cosmotropic salt, and the temperature that precipitates a particular concentration of a particular water-soluble, cationic polymer can be carried out in a number of ways. One way is by the cloud temperature technique described above. For example, to determine the cloudiness temperatures of the 1% poly (DMAEM.MeCl) one can prepare 30 samples of the 1% aqueous poly (DMAEM.MeCl), each containing either 0%, 5% ammonium sulfate, 10%, 15%, or 20%, and either sodium thiocyanate at 0%, 2%, 4%, 6%, 8% or 10%, in all combinations. Samples that have 0% salt are control samples. The cloudiness temperatures of each solution can be determined by heating each sample to dissolve the polymer, then cooling until the solution changes to cloudy. Turbidity will indicate precipitation, and the temperature at which it occurs should be the cloudiness temperature. The process can be repeated for any other polymer, polymer concentration or salts. Typically, most samples remain clear, even below 0 ° C, or lower, while others remain cloudy with heating, even at 100 ° C or higher. Although one will not obtain the cloud temperature information from these samples, one will know the phase behavior of the particular polymer for that particular salt system. In cases when precipitation is observed with heating, and the polymer dissolves upon cooling, the cloudiness temperatures must be determined by cooling the mixtures until the polymers dissolve, then heating to precipitate the polymer. In these cases, the cloudiness temperatures will be the temperatures at which turbidity is observed with heating.

The cloudiness temperatures necessary to determine the effective amounts of chaotropic salt, or anionic organic salt, and cosmotropic salt to precipitate a particular water-soluble polymer at a particular temperature. For example, one can prepare a series of solutions containing various amounts of chaotropic salt, or anionic organic salt, and cosmotropic salt, and then add a polymer solution to each salt solution. The polymer will either precipitate or remain soluble, as determined by simple visual inspection, and the polymer's solubility behavior can be correlated with the type and concentration of each salt. For example, Examples 23-41 show that the total level of salt useful for precipitating a cationic polymer may be lower when a mixture of chaotropic salt, or anionic organic salt, and cosmotropic salt, compared to the use of a single salt, is used. cosmotropic Another routine experimental process for identifying effective amounts of salts that will precipitate a particular cationic polymer at a particular temperature is to polymerize the monomers in the salt solution, then determine the cloudiness temperatures. This technique is preferred at high concentrations of polymer, because concentrated solutions of polymers, for example, 10% or greater, can be difficult to handle, for example, stir. The process is similar to the cloud temperature process in that one can take a series of salt solutions in which the monomer or monomers will dissolve at concentrations necessary to provide the desired polymer concentration. The solutions can then be polymerized in a known manner, for example, by spraying with inert gas, such as nitrogen, then polymerization initiated by a conventional free radical initiator, to form mixtures of the polymers and salts. Then the cloudiness temperatures of the mixtures can be determined as mentioned above.

The routine experimental process to identify the effective amounts of salts that will not dissolve powders or granules of water-soluble polymer, substantially particular dry at a particular temperature is similar to the process described above. One can also take a series of salt solutions as mentioned above, then add dry polymer to give a composition with the desired polymer concentration. The mixtures can then be stirred and heated to effect the dissolution of the polymer. Then the information can be obtained, by direct observation, as to whether the polymer dissolves or does not dissolve in any particular solution; and the information of the behavior of the temperature-dependent phase can be obtained from those solutions which exhibit a cloudiness temperature as described above.

The precipitated polymer can be recovered from the solution by any means known in the art, including filtration, centrifugation, evaporation, spray drying, combinations thereof, etc. The recovered polymer granules typically contain cationic water-soluble polymer, residual salts, residual dispersant optionally, and water. Preferably, the resulting polymer granules contain less than about 30% water, more preferably from about 0.1% to about 20%. Polymer granules of free flowing, substantially dry, ie containing less than about 10% H20, are preferred for handling purposes. Various pH adjusting agents, flow control agents, preservatives, agents for particle size control, etc. which are known to those skilled in the art can be added, at any stage of the process, to give substantially dry granules containing water-soluble, cationic polymer.

The compositions and processes of this invention provide water-soluble cationic polymers that are useful in a number of applications, for example, flocculation of dispersions of suspended solids, recovery of minerals from mining operations, papermaking, oil recovery. increased, treatment of refinery waste, treatment of waste paper, treatment of food waste, etc. Dispersions of suspended solids can be biologically treated suspensions. It is effective in these applications that the precipitated polymer compositions can be added directly to a dispersion of suspended solids to be treated, mixed, and the resulting concentrated dispersion separated by means known in the art, such as centrifuge, belt press. , filter press, filter, etc. Preferably, the compositions are first diluted in water to form solutions having a cationic polymer concentration of from about 0.01 to about 10%, preferably about 0.05 to about 5%, more preferably about 0.1 to about 3%. Then the diluted polymer solution can be mixed in a known manner with the dispersion of suspended solids to be treated, and the resulting concentrated dispersion is separated as mentioned above. It is known to those skilled in the art that the amount of diluted polymer solution effective for a particular application can be found through routine experimentation, as illustrated in Examples R and 20-22, below. A particularly preferred application is the treatment of dispersions of suspended solids, which comprise a biologically treated suspension.

Substantially dried polymer granules and polymer dispersions are preferred because the small granule or droplet size of the polymer helps dissolve the polymer more rapidly in dilution. It is believed that the polymer dissolves, in spite of the presence of the salts, which tend to precipitate this, because the salt concentration is reduced from the effective range for the precipitation to a range that allows to dissolve the polymer, by dilution.

Another preferred application for the water-soluble cationic polymers of the present invention is soil conditioning, for example, for the prevention of soil erosion. The irrigation process of a field may tend to cause the damaging loss of a valuable top layer of soil by erosion. The soil can be stabilized against erosion, particularly in situations, where the soil is irrigated, by a process which comprises the addition to the soil of an amount for soil conditioning of an aqueous composition composed of an effective amount of 1. less a chaotropic salt, or anionic organic salt, an effective amount of at least one cosmotropic salt, and at least one polymer soluble in precipitated cationic water. The addition of the polymer to the soil in an amount for soil conditioning tends to produce a greater cohesiveness among the soil particles, so that the soil is stabilized against erosion by wind, water, etc. Preferably, the composition is dissolved in water to form a conditioning solution, which can then be applied to the soil, preferably further, or replaced by, the water typically used to irrigate a field. Alternatively, and less preferably, the dispersions of polymer or dry polymer can be applied substantially directly to the soil. In these cases, the polymer can form a conditioning solution when combined with water already present in the soil, or by the subsequent application of water to dissolve the polymer. In irrigation applications, the amounts for soil conditioning generally range from about 0.1 to about 20 pounds of polymer per acre per year, preferably 0.5 to 10 pounds of polymer per acre per year.

Soil erosion can also take the form of a large-scale movement of soil, for example, landslides where the soil is not typically irrigated. For example, the destruction of vegetation on a hillside by, for example, fire can leave the underlying soil unstable and prone to movement. In these applications, different irrigation media, such as spray, can be used to apply the conditioning solutions. Alternatively, polymer or dry polymer dispersions can be applied directly to the soil. In these cases, the polymer can form a conditioning solution when combined with water already present in the soil, or by subsequent application of water to dissolve the polymer.

The following examples are set forth for purposes of illustration only and are not construed as limiting the present invention.

STANDARD POLYMER VISCOSITY The standard viscosity is the viscosity of a 0.096% solution of water-soluble polymer in IN sodium chloride at 25 ° C. The viscosity is measured by a Brookfield LVT viscometer with an Ultraviolet Light adapter at 60 rpm. The polymer solution that is measured is made by diluting a dispersion or polymer solution to a concentration of 0.2% by agitation with the appropriate amount of deionized water for approximately 12 hours, and then by diluting with the appropriate amounts of deionized water and chloride of water. sodium.

EXAMPLE A A 40% poly (DMAEM.MeCl) solution is prepared as follows: 160 parts of a DMAEM solution. 75% MeCl, 140 parts of deionized water and 0.120 parts of 2,2'-azobis [2- (2-imidazdin-2-yl) propane] dihydrochloride, then VA-044, an azo initiator, are added to an appropriate container. The solution is sprayed with nitrogen gas and stirred for about one hour at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is thermally initiated by increasing the temperature of the solution to 44 ° C. Stirring and heating are carried out for approximately 21 hours. The vessel is cooled to give a viscous, clear poly (DMAEM.MeCl) solution having a standard viscosity of about 1.4 centipoise.

EXAMPLE B A solution of 20% poly (DMAEM.MeCl) is prepared as follows: 80 parts of a 75% DMAEM.MeCl solution, 220 parts of deionized water and 0.015 parts of VA-044 are added to a suitable glass container . The solution is sprayed with nitrogen gas and the solution is stirred for about one hour at room temperature. The nitrogen mist is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp. Stirring and heating are carried out for 3 hours to give a viscous, clear poly (DMAEM.MeCl) solution having a standard viscosity of about 1.4 centipoise.

EXAMPLES C-D The temperature-dependent solubility behavior of the poly (DMAEM.MeCl) prepared as in Example A is determined by measuring the cloudiness temperatures in the sodium thiocyanate solution as follows: Poly (DMAEM.MeCl) polymer solution 40% is diluted in deionized water to give a 1% solution. A part of the 1% polymer solution is added to a first clear glass vessel. A solution of 3.24% NaSCN is prepared in a second vessel, and 1 part of the 3.24% NaSCN solution is added to the first glass vessel containing 1 part of 1% poly (DMAEM.MeCl), with stirring. The resulting clear solution in the first vessel has a polymer concentration of 0.5% and a NaSCN concentration of 1.62%. The first vessel is cooled in an ice bath, and it is observed that the polymer precipitates, as demonstrated by the appearance of turbidity in the vessel, at a temperature of 16 ° C. Therefore, the clouding temperature of the poly (DMAEM.MeCl) at 0.5% in NaSCN at 1.62% is 16 ° C. Similarly, the clouding temperature of the 0.5% poly (DMAEM, MeCl), prepared as in Example B, in 1.62% NaSCN is also 16 ° C.

EXAMPLE E The procedure of Example C is repeated, except that the concentration of NaSCN in the second vessel is adjusted, so that the concentration of NaSCN resulting in the first vessel is 3.24%. In this case, turbidity indicative of precipitation at room temperature is observed. The first container is heated to dissolve the polymer, forming a clear solution. With cooling, turbidity indicative of precipitation at 30 ° C is observed. Therefore, the clouding temperature of the poly (DMAEM, eCl) at 0.5% in NaSCN at 3.24% is 30 ° C.

EXAMPLE 1 The procedure of Example C is repeated, except that the solution in the second vessel contains 6.48% NaSCN and 10% (NH4) 2S04. The resulting concentration of the NaSCN in the first vessel is therefore 3.24%, and the resulting concentration of (NH4) 2S04 is 5%. In this case, turbidity indicative of precipitation at room temperature is observed. The first container is heated to dissolve the polymer, forming a clear solution. With cooling, turbidity indicative of precipitation at 38 CC is observed. Therefore, the fouling temperature of the poly (DMAEM.MeCl) at 0.5% in NaSCN at 3.24% and (NH4) 2S04 at 5% is 38 ° C, as compared to 30 ° C (Example E) when it is absent (NH4) 2S0.

EXAMPLE 2 The procedure of Example C is repeated, except that the solution in the second vessel contains 6.48% NaSCN and 20% (NH4) 2SO. The resulting concentration of the NaSCN in the first vessel is therefore 3.24%, and the resulting concentration of (NH) 2S04 is 10%. In this case, turbidity indicative of precipitation at room temperature is observed. The first container is heated to dissolve the polymer, forming a clear solution. With cooling, turbidity indicative of precipitation at 60 ° C is observed. Therefore, the clouding temperature of the poly (DMAEM.MeCl) at 0.5% in NaSCN at 3.24% and (NH4) 2S04 at 10% is 60 ° C.

EXAMPLE 3 A solution of 20% poly (DMAEM.MeCl) is prepared in the presence of 5% NaSCN and 10% (NH) 2 SO4 by adding 80 parts of a DMAEM solution. 75% MeCl, 15 parts of NaSCN, 30 parts of (NH4) 2S04, 175 parts of deionized water and 0.060 parts of VA-044 to an appropriate container. The solution is sprayed with nitrogen gas and stirred for about one hour at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is thermally initiated by increasing the temperature of the solution to 44 ° C. Stirring and heating are carried out for approximately 21 hours, then cooled to give an opaque, white mixture. The mixture is heated to dissolve the polymer and a clear solution is formed. With cooling, turbidity indicative of precipitation at 39 ° C is observed. Therefore, the clouding temperature of the poly (DMAEM.MeCl) at 0.5% in 5% NaSCN and 10% (NH4) 2S04 is 39 ° C. The standard viscosity of the polymer is 1.5 centipoise.

EXAMPLE F The temperature-dependent solubility behavior of the poly (DMAEM.MeCl) prepared as in Example A is determined by measuring the cloudiness temperatures in the sodium 3-nitrobenzenesulfonate solution as follows: Poly (DMAEM. MeCl) at 40% is diluted in deionized water to give a 1% solution. A part of the 1% polymer solution is added to a clear glass vessel. 0.04 Parts of sodium 3-nitrobenzenesulfonate and 0.96 parts of deionized water are added to the glass vessel containing 1 part of poly (DMAEM.MeCl) at 1%, with stirring.

The resulting mixture has a polymer concentration of 0.5% and a concentration of sodium 3-nitrobenzenesulfonate of 2.0%.

The vessel is heated to produce a clear solution, then it is cooled. The polymer is observed to precipitate, as evidenced by the appearance of turbidity in the vessel, at a temperature of 26 ° C. Therefore, the clouding temperature of the poly (DMAEM.MeCl) at 0.5% in sodium 3-nitrobenzenesulfonate at 2.0% is 26 ° C.

EXAMPLE 4 The temperature-dependent solubility behavior of the poly (DMAEM.MeCl) prepared as in Example A is determined by measuring the cloudiness temperatures in a solution containing (NH4) 2S04 and sodium 3-nitrobenzenesulfonate as follows: 40% poly (DMAEM.MeCl) polymer is diluted in deionized water to give a 1% solution. A part of the 1% polymer solution is added to a clear glass vessel. 0.04 Parts of sodium 3-nitrobenzenesulfonate, 0.4 parts of (NH4) 2S04 and 0.56 parts of deionized water are added to the glass vessel containing 1 part of poly (DMAEM.MeCl) at 1%, with stirring. The resulting mixture has a polymer concentration of 0.5%, a concentration of sodium 3-nitrobenzenesulfonate of 2.0%, and a concentration of (NH4) 2S04 of 20%. The vessel is heated to produce a clear solution, then allowed to cool. The polymer is observed to precipitate, as evidenced by the appearance of turbidity in the vessel, at a temperature of 81 ° C. Therefore, the clouding temperature of the poly (DMAEM.MeCl) at 0.5% in 2.0% sodium 3-nitrobenzenesulfonate and 20% (NH4) 2S04 is 81 ° C, as compared to 26 ° C (Example F). ) when (NH4) 2S04 is absent.

EXAMPLE G A solution of poly [3-acrylamido (3-methylbutyl) trimethylammonium chloride], or 15% poly (AMBTAC), is prepared as follows: 15 parts of AMBTAC monomer and 83 parts of deionized water are added to an appropriate container . The solution is sprayed with nitrogen gas and stirred for about one hour at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by adding 0.33 parts of 1% ammonium persulfate solution sprayed with nitrogen with a syringe and 0.33 pallets of 1% ammonium bisulfite solution sprayed with nitrogen with a syringe. An additional 0.33 parts of 1% ammonium persulfate solution sprayed with nitrogen and 0.33 parts of 1% sodium bisulfite solution sprayed with nitrogen are added with a syringe after two hours, and another addition of the same amounts of the initiators are added for four hours after the initial addition. Finally, 0.02 parts of VA-044 are added eight hours after the initial addition. Stirring is continued for approximately 18 hours. A viscous, clear poly (AMBTAC) solution results.

EXAMPLE 5 The temperature-dependent solubility behavior of the poly (AMBTAC) prepared as in Example G is determined by measuring the cloudiness temperatures in a solution containing (NH) 2S0 and sodium thiocyanate as follows: Poly ( AMBTAC) at 15% is diluted in deionized water to give a 1% solution. A part of the 1% polymer solution is added to a clear glass vessel. 0.04 Parts of sodium thiocyanate, 0.1 parts of (NH4) 2S04, and 0.86 parts of deionized water are added to the glass vessel containing 1 part of poly (AMBTAC) at 1%, with stirring. The resulting mixture has a polymer concentration of 0.5%, a concentration of sodium thiocyanate of 2.0%, and a concentration of (NH4) 2S0 of 5%. The vessel is heated to produce a clear solution, then allowed to cool. The polymer is observed to precipitate, as demonstrated by the appearance of turbidity in the vessel, at a temperature of 44 ° C. Therefore, the opacification temperature of the poly (AMBTAC) at 0.5% in 2.0% sodium thiocyanate and 5% (NH4) 2S04 is 44 ° C.

EXAMPLE 6 The procedure of Example 5 is repeated, except that the concentration of sodium thiocyanate is 3.0%. In this case, the polymer is observed to precipitate, as demonstrated by the appearance of turbidity in the vessel, at a temperature of 70 ° C. Therefore, the opacification temperature of the poly (AMBTAC) at 0.5% in 3.0% sodium thiocyanate and 5% (NH4) 2S0 is 70 ° C.

EXAMPLE H A 40% poly (DMAEA.MeCl) solution is prepared as follows: 160 parts of a 75% DMAEA.MeCl solution (the methyl chloride quaternary dimethylaminoethylacrylate salt), 140 parts of deionized water and 0.120 parts of VA-044 are added to an appropriate container. The solution is sprayed with nitrogen gas and stirred for about one hour at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is thermally initiated by increasing the temperature of the solution to 44 ° C. Stirring and heating are continued for approximately 21 hours. The vessel is cooled to give a viscous, clear poly (DMAEA.MeCl) solution having a standard viscosity of about 2.3 centipoise.

EXAMPLE 7 The temperature-dependent solubility behavior of the poly (DMAEA.MeCl) prepared as in Example H is determined by measuring the cloudiness temperatures in a solution containing (NH4) 2S04 and sodium thiocyanate as follows: The polymer solution of 40% poly (DMAEA.MeCl) is diluted in deionized water to give a 1% solution. A part of the 1% polymer solution is added to a clear glass vessel. 0.10 Parts of sodium thiocyanate, 0.1 parts of (NH4) 2S0, and 0.80 parts of deionized water are added to the glass vessel containing 1 part of the poly (DMAEA.MeCl) at 1%, with stirring. The resulting mixture has a polymer concentration of 0.5%, a concentration of sodium thiocyanate of 5%, and a concentration of (NH4) 2S04 of 5%. The vessel is heated to produce a clear solution, then allowed to cool. The polymer is observed to precipitate, as evidenced by the appearance of turbidity in the vessel, at a temperature of 35 ° C. Therefore, the clouding temperature of poly (DMAEA.MeCl) at 0.5% in 5% sodium thiocyanate and 5% (NH4) 2S04 is 35 ° C.

EXAMPLE I A solution of 40% poly (DMAEM.DMS) is prepared as follows: 160 parts of a 75% DMAEM solution.DMS (dimethylaminoethylmethacrylate quaternary dimethyl sulfate salt), 140 parts of deionized water and 0.120 parts. of VA-044 are added to an appropriate container. The solution is sprayed with nitrogen gas and stirred for about one hour at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is thermally initiated by increasing the temperature of the solution to 44 ° C. Stirring and heating are continued for about 18 hours. The vessel is cooled to give a viscous, clear poly (DMAEM.DMS) solution having a standard viscosity of about 1.3 centipoise.

EXAMPLE 8 The temperature-dependent solubility behavior of the poly (DMAEM.DMS) prepared as in Example I is determined by measuring the cloudiness temperatures in a solution containing (NH4) 2S04 and sodium thiocyanate as follows: The polymer solution of Poly (DMAEM.DMS) at 40% is diluted in deionized water to give a 1% solution. A part of the 1% polymer solution is added to a clear glass vessel. 0.10 Parts of sodium thiocyanate, 0.1 parts of (NH) 2S04, and 0.80 parts of deionized water are added to the glass vessel containing 1 part of poly (DMAEM.DMS) at 1%, with stirring. The resulting mixture has a polymer concentration of 0.5%, a concentration of sodium thiocyanate of 5%, and a concentration of (NH4) 2S04 of 5%. The vessel is heated to produce a clear solution, then allowed to cool. The polymer is observed to precipitate, as evidenced by the appearance of turbidity in the vessel, at a temperature of 49 ° C. Therefore, the clouding temperature of the poly (DMAEM.DMS) at 0.5% in 5% sodium thiocyanate and 5% (NH4) 2S04 is 49 ° C.

EXAMPLE 9 A copolymer containing about 45 mol% of DMAEA.MeCl, 42 mol% of acrylamide (AMD) and 13 mol% of ethyl acrylate (EA) is prepared by polymerizing the monomers in the presence of 15% (NH4) 2S04 and 1%., 6.75% 3-benzenedisulfonate as follows: 16.8 parts of an 80% DMAEA.MeCl solution, 8.6 parts of a 53% acrylamide solution, 2.0 parts of ethyl acrylate, 15 parts of (NH4) 2S04, and 7.94 parts of 1,3-benzenedisulfonate at 85% and 44.66 parts of deionized water are added to a glass vessel, with stirring, to form a clear solution. 1.0 Parts of a solution comprising 0.004 parts of VA-044 per part of solution is added, along with 0.4 parts of a 5% solution of sodium ethylenediaminetetraacetate (EDTA) and 3.6 parts of deionized water. EDTA is a chelating agent and is added to prevent the inhibition of polymerization by metal ions. The resulting clear solution is sprayed with nitrogen, with stirring, for 30 minutes. The spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the container to an ultraviolet light lamp. The exposure to the lamp is continued for 45 minutes. The product is white and contains precipitated polymer with a standard viscosity of approximately 2.5 centipoise.

EXAMPLE J A 10% solution of a copolymer containing about 55 mol% DMAEA.MeCl and 45 mol% acrylamide (AMD) is prepared as follows: 4.81 parts of a DMAEM solution. 80% MeCl, 2.18 parts of a 53% acrylamide (AMD) solution, 0.63 parts of a solution comprising 0.002 parts of VA-044 per part of solution, 0.1 part of a solution of sodium ethylenediaminetetraacetate (EDTA) 5% and 42.28 parts of deionized water are added to an appropriate glass container. The solution is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. A clear, viscous 10% viscous poly (55-DMAEA.MeCl / 45-AMD) solution having a standard viscosity of about 1.4 centipoise results.

EXAMPLE K A 10% solution of a copolymer comprising DMAEA.MeCl at 75% mol and acrylamide (AMD) at 25% mol is prepared as follows: 5.57 parts of an 80% DMAEM.MeCl solution, 1.03 parts of a 53% acrylamide (AMD) solution, 0.63 parts of a solution comprising 0.002 parts of VA-044 per part of solution, 0.1 parts of a 5% solution of sodium ethylenediaminetetraacetate (EDTA) and 42.67 parts of deionized water are added to an appropriate glass vessel. The solution is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. A clear, viscous 10% viscous poly (75-DMAEA.MeCl / 25-AMD) solution having a standard viscosity of about 1.4 centipoise results.

EXAMPLE 10 The temperature-dependent solubility behavior of the poly (55-DMAEA.MeCl / 45-AMD) prepared as in Example J is determined by measuring the cloudiness temperatures in a solution containing (NH4) 2S04 and 1,3-benzenedisulfonate of sodium as follows: The 10% poly (55-DMAEA.MeCl / 45-AMD) polymer solution is diluted in deionized water to give a 1% solution. 0.051 Parts of sodium 1,3-benzenedisulfonate, 0.4 parts of (NH4) 2S0, and 0.549 parts of deionized water are added to a clear glass vessel containing 1 part of poly (55-DMAEA.MeCl / 45-AMD) at 1%, with agitation. The resulting mixture has a polymer concentration of 0.5%, a concentration of sodium 1,3-benzenedisulfonate of 2.55%, and a concentration of (NH4) 2S04 of 20%. The vessel is heated to produce a clear solution, then allowed to cool. The polymer is observed to precipitate, as evidenced by the appearance of turbidity in the vessel, at a temperature of 53 CC. Therefore, the fouling temperature of the poly (55-DMAEA.MeCl / 45-AMD) at 0.5% in 1, 3-sodium benzenedisulfonate at 2.55% and (NH4) 2S04 is 53 ° C.

EXAMPLE 11 The temperature-dependent solubility behavior of the poly (75-DMAEA.MeCl / 25-AMD) prepared as in Example K is determined by measuring the cloudiness temperatures in a solution containing (NH) 2S04 and 1,3-benzenedisulfonate of sodium as follows: The 10% poly (75-DMAEA.MeCl / 25-AMD) polymer solution is diluted in deionized water to give a 1% solution. 0.051 Parts of 1,3-sodium benzenedisulfonate, 0.4 parts of (NH) 2S04, and 0.549 parts of deionized water are added to a clear glass vessel containing 1 part of poly (55-DMAEA.MeCl / 45-AMD) at 1%, with agitation. The resulting mixture has a polymer concentration of 0.5%, a concentration of sodium 1,3-benzenedisulfonate of 2.55%, and a concentration of (NH4) 2S04 of 20%. The vessel is heated to produce a clear solution, then allowed to cool. The polymer is observed to precipitate, as evidenced by the appearance of turbidity in the vessel, at a temperature of 66 ° C. Therefore, the clouding temperature of the poly (75-DMAEA.MeCl / 25-AMD) at 0.5% in 1, 3-benzenedisulfonate at 2.55% sodium and (NH4) 2S04 at 20% is 66 ° C, as compare at 53 ° C for the poly (55-DMAEA.MeCl / 45-AMD) of Example 10.

EXAMPLE L A 40% solution of a copolymer comprising 55% mol DMAEA.MeCl and 45% molar acrylamide (AMD) is prepared as follows: 19.23 parts of an 80% DMAEM.MeCl solution, 8.85 parts of a solution of Acrylamide (AMD) at 52.21%, 2 parts of a solution comprising 0.01 parts of VA-044 per part of solution, 0.4 parts of a solution of 5% ethylenediaminetetraacetate sodium (EDTA), 2.5 parts of isopropyl alcohol and 17.03 Deionized water parts are added to an appropriate glass container. The solution is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. A clear, 40% viscous poly (55-DMAEA.MeCl / 45-AMD) solution having a standard viscosity of about 1.3 centipoise results.

EXAMPLE 12 The temperature-dependent solubility behavior of the poly (55-DMAEA.MeCl / 45-AMD) prepared as in Example L is determined by measuring the cloudiness temperatures in a solution containing (NH4) 2S04 and sodium diisobutylsulfosuccinate as follows : The 40% poly (55-DMAEA.MeCl / 45-AMD) polymer solution is diluted in deionized water to give a 1% solution. 0.0404 Parts of sodium diisobutylsulfosuccinate, 0.1 parts of (NH4) 2S04 and 0.8596 parts of deionized water are added to a clear glass vessel containing 1 part of poly (55-DMAEA.MeCl / 45-AMD) at 1%, with agitation. The resulting mixture has a polymer concentration of 0.5%, a concentration of sodium diisobutylsulfosuccinate of 2.02%, and a concentration of (NH4) 2S04 of 5%. The vessel is heated to produce a clear solution, then allowed to cool. The polymer is observed to precipitate, as demonstrated by the appearance of turbidity in the vessel, at a temperature of 55 ° C. Therefore, the clouding temperature of the poly (55-DMAEA.MeCl / 45-AMD at 0.5% in sodium diisobutylsulfosuccinate at 2.02% and (NH4) 2S04 at 5% is 55 ° C.

EXAMPLE 13 The temperature-dependent solubility behavior of the poly (55-DMAEA.MeCl / 45-AMD) prepared as in Example L is determined by measuring the cloudiness temperatures in a solution containing (NH4) 2S04 and sodium diisobutylsulfosuccinate as follows : The 40% poly (55-DMAEA.MeCl / 45-AMD) polymer solution is diluted in deionized water to give a 1% solution. 0.0132 Parts of sodium diisobutylsulfosuccinate, 0.3 parts of (NH4) 2S04 and 0.6868 parts of deionized water are added to a clear glass container containing 1 part of poly (55-DMAEA.MeCl / 45-AMD) at 1%, with agitation. The resulting mixture has a polymer concentration of 0.5%, a concentration of sodium diisobutylsulfosuccinate of 0.66%, and a concentration of (NH4) 2S0 of 15%. The vessel is heated to produce a clear solution, then allowed to cool. The polymer is observed to precipitate, as evidenced by the appearance of turbidity in the vessel, at a temperature of 50CC. Therefore, the clouding temperature of poly (55-DMAEA.MeCl / 45-AMD at 0.5% in sodium diisobutylsulfosuccinate at 0.66% and (NH4) 2S04 at 15% is 50 ° C.

EXAMPLE 14 A dispersion of a polymer containing 55% mol DMAEA.MeCl and 45% mol AMD is prepared as follows: 19.3 parts of 80% DMAEA.MeCl, 8.6 parts of 53% AMD, 15 parts of ammonium sulfate, 8.44 parts of solid 1, 3 -benzenedisulfonate (80%) technical, 1 part of a solution containing 0.004 parts of VA-044 per part of solution, 0.4 parts of a 5% solution of sodium ethylenediaminetetraacetate (EDTA), and 47.26 parts of deionized water are added to a suitable clear glass vessel and stirred to form a clear solution. The solution is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. The product is a white dispersion that shows a yield stress, with a standard viscosity of approximately 2.2 centipoise.

EXAMPLE M A 20% solution of a nonionic dispersant containing 98% AMD mol and 2% t-butyl acrylamide mole is prepared as follows: 36.42 parts of 53% AMD, 0.7 parts of t-butyl acrylamide, parts of isopropanol, 1 part of a solution containing 0.004 parts of VA-044 per part of solution, 0.4 parts of a 5% solution of sodium ethylenediaminetetraacetate (EDTA), and 58.48 parts of deionized water are added to a container of appropriate clear glass and shake to form a clear solution. The solution is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. The product is a viscous, clear polymer solution, with a standard viscosity of approximately 1.4 centipoise.

EXAMPLE 15 A dispersion of a polymer containing 55% mol DMAEA.MeCl, 43% mol AMD and 2% t-butyl acrylamide mole is prepared in the presence of a dispersant prepared as in Example M as follows: 5 parts of a 20% polymer solution prepared as in Example M, 19.08 parts of 80% DMAEA.MeCl, 8.26 parts of 53% AMD, 0.36 parts of t-butyl acrylamide, and 42.9 parts of deionized water are added to a suitable glass container and shake to dissolve the polymer. 15 Parts of ammonium sulfate, 7.94 parts of solid 1, 3-benzene sulfonate (85%) technical, 1 part of a solution containing 0.004 parts of VA-044 per part of solution, and 0.4 parts of a solution of ethylenediaminetetraacetate of sodium (EDTA) at 5% are added and stirred. The mixture is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. The product is a white dispersion that shows a yield stress, with a standard viscosity of approximately 2.3 centipoise.

EXAMPLE N A 20% solution of a non-ionic polyacrylamide dispersant is prepared as follows: 37.24 parts of 53% AMD, 3 parts of isopropanol, 1 part of a solution containing 0.004 parts of VA-044 per part of solution, 0.4 parts of a 5% solution of sodium ethylenediaminetetraacetate (EDTA), and 58.36 parts of deionized water are added to a suitable clear glass vessel and stirred to form a clear solution. The solution is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. The product is a viscous, clear polymer solution, with a standard viscosity of approximately 1.4 centipoise.

EXAMPLE 16 A dispersion of a polymer containing DMAEA.MeCl at mole% and 45% MoD AMD is prepared in the presence of a dispersant prepared as in Example N as follows: 6 parts of a 20% polymer dispersant solution prepared as in Example N, 9.61 parts of DMAEA. 80% MeCl, 2.31 parts of AMD at 53%, and 57.94 parts of deionized water are added to an appropriate glass vessel and stirred to dissolve the polymer. 15 Parts of ammonium sulfate, 7.94 parts of solid 1, 3-benzenedisulfonate (85%) technical sodium, 1 part of a solution containing 0.002 parts of VA-044 per part of solution, and 0.2 parts of a solution of ethylenediaminetetraacetate of sodium (EDTA) at 5% are added and stirred. The mixture is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. The product is a white dispersion that shows a yield stress.

EXAMPLE 17 (Comparison) This experiment is carried out exactly as in Example 16, except that 6 parts of deionized water are used in place of 6 parts of dispersant. Both dispersions were initially stirred, but the dispersion without the dispersant settles within a few hours, while the dispersion which contains the dispersant is still stirred after 24 hours.

EXAMPLE O A 20% solution of an anionic dispersant containing 99% mol% acrylamide and 1 mol% sodium acrylamidomethylpropanesulfonate is prepared as follows: 18.54 parts of AMD at 52.2%, 0.63 parts of sodium 2-acrylamido-2-methylpropanesulfonate at 50%, 1.5 parts of isopropanol, 1.25 parts of a solution containing 0.002 parts of VA-044 per part of solution, 0.2 parts of a 5% solution of sodium ethylenediaminetetraacetate (EDTA), and 27.88 parts of deionized water are added to a clear glass vessel and shake to form a clear solution. The solution is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. The product is a viscous, clear polymer solution, with a standard viscosity of approximately 1.5 centipoise.

EXAMPLE 18 A dispersion of a polymer containing 55% DMAEA.MeCl mole and 45% mole AMD is prepared in the presence of a dispersant prepared as in Example 0 as follows: 6 parts of a polymer dispersant solution prepared as in US Pat. Example 0, 15 parts of ammonium sulfate, 7.91 parts of solid 1, 3-benzenedisulfonate (85%) technical sodium, 0.2 parts of a 5% solution of sodium ethylenediaminetetraacetate (EDTA), and 45.89 parts of deionized water is add to a first glass container and stir to dissolve the polymer, forming a salt solution. 9.61 Parts of 80% DMAEA.MeCl, 4.42 parts of AMD at 52.2%, 1.25 parts of a solution containing 0.002 parts of VA-044 per part of solution, and 9.72 parts of deionized water are added to a second vessel, forming a monomer solution. Both the monomer solution and the salt solution are sprayed with nitrogen about 15 minutes at room temperature. The monomer solution is added dropwise to the salt solution at a rate of about 0.4 parts per minute, during which the salt solution is stirred under a nitrogen purge and exposed to an ultraviolet light lamp. After the addition is complete, the resulting white dispersion is stirred for an additional hour. The product is a white dispersion that is still stirred after a day. 1 EXAMPLE P A 20% solution of a cationic dispersant containing 90% acrylamide mole and 10% DEAEA.MeCl mole is prepared as follows: 14.22 parts of AMD at 52.2%, 2.57 parts of DEAEA.MeCl, 1.5 parts of isopropanol, 1.25 Parts of a solution containing 0.002 parts of VA-044 per part of solution, 0.2 parts of a 5% solution of sodium ethylenediaminetetraacetate (EDTA), and 30.25 parts of deionized water are added to an appropriate glass vessel and shaken to form a clear solution. The solution is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about one hour. The product is a viscous, clear polymer solution, with a standard viscosity of approximately 1.4 centipoise.

EXAMPLE 19 A dispersion of a polymer containing DEAEA.MeCl at 55 mol% and AMD at 45 mol% is prepared in the presence of a dispersant prepared as in Example P as follows: 6 parts of a 20% polymer dispersant solution prepared as in Example P, 10 parts of ammonium sulfate, 7.12 parts of solid 1, 3-benzenedisulfonate (85%) technical sodium, 0.2 parts of a 5% solution of sodium ethylenediaminetetraacetate (EDTA), and 51.68 parts of deionized water are added to a first glass container and stir to dissolve the polymer, forming a salt solution. 7.92 Parts of DEAEA.MeCl, 3.98 parts of AMD at 52.2%, 1.25 parts of a solution containing 0.002 parts of VA-044 per part of solution, and 11.85 parts of deionized water are added to a second vessel, forming a solution of monomer Both the monomer solution and the salt solution were sprayed with nitrogen for about 15 minutes at room temperature. The monomer solution is added dropwise to the salt solution at a rate of about 0.4 parts per minute, during which the salt solution is stirred under a nitrogen purge and exposed to an ultraviolet light lamp. After the addition is complete, the resulting white dispersion is stirred for an additional hour. The product is a white dispersion that is still stirred after a day.

EXAMPLE Q A 20% solution of a copolymer containing about 55 mol% DMAEA.MeCl and 45 mol% acrylamide (AMD) is prepared as follows: 9.62 parts of a DMAEM solution. 80% MeCl, 4.36 parts of a 53% acrylamide (AMD) solution, 1 part of a solution that has 0.01 part of VA-044 per part of solution, 0.2 part of a solution of sodium ethylenediaminetetraacetate (EDTA) 5% and 34.82 parts of deionized water are added to an appropriate glass container. The solution is sprayed with nitrogen gas and stirred for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge and the polymerization is initiated by exposing the glass container to ultraviolet light for about one hour. A clear, viscous 20% viscous poly (55-DMAEA.MeCl / 45-AMD) solution having a standard viscosity of about 3.1 centipoise results.

EXAMPLE R A 0.2% poly (55-DMAEA.MeCl / 45-AMD) solution is prepared by stirring .1 parts of a solution of poly (55-DMAEA.MeCl / 45-AMD) prepared as in Example Q in 16.4 parts of water to form a clear 4% solution, then adding 389.5 parts of deionized water and stirring.

EXAMPLE 20 A 4% poly (55-DMAEA.MeCl / 45-AMD) solution is prepared by stirring 4.1 parts of a solution of poly (55-DMAEA.MeCl / 45-AMD) prepared as in Example Q in 16.4 parts of water . This solution is mixed with 20.5 parts of a solution containing 2.05 parts of ammonium sulfate and 2.46 parts of sodium benzenesulfonate to give a composition containing precipitated polymer and aqueous salt. Then this composition, which is 2% polymer, 5% ammonium sulfate and 6% sodium benzenesulfonate, is diluted by agitation with 369 parts of water to form a solution of poly (55-DMAEA.MeCl / 45- AMD) at 0.2%.

EXAMPLES 21 and 22 The performance of the polymers prepared in the Examples R and 20 are evaluated by measuring their ability to flocculate suspended solids in a biologically treated slurry (sludge). The level of solids in the mud is 1.88%. The procedure of 14 The evaluation is carried out as follows: 15 parts of the 0.2% polymer solution of Example R are mixed vigorously with 200 parts of the mud for 5 seconds, then filtered. The number of filtrate parts, which are drained freely through the filter in 10 seconds, is measured and recorded (free drain in 10 seconds). The procedure is repeated using 17, 19, 21 and 23 parts of 0.2% polymer solution, then repeated in an identical manner for the 0.2% polymer solution of Example 20. Free draining in 10 seconds for both polymers is shown in Table 11 and (plotted in Figure 11) as a function of the polymer dose, where the dose is expressed in units of polymer pounds per dry ton of mud (lbs./DT). Table 11 (Figure 11) shows that the flocculation performance of the precipitated polymer (Example 20) is comparable to the flocculation performance of the polymer in solution (Example R) at lower dosages, but higher than higher dosages.

Table 11. Free Drainage in 10 Seconds of Flocculated Solids as a Function of the Polymer Dose for Precipitated Polymers and in Solution.

EXAMPLE S A 2% solution of a copolymer containing approximately 20 mol% DMAEA.MeCl, 20 mol% DMAEA.BzCl, and 60 mol% acrylamide (AMD) is prepared as follows: 1.43 parts of a DMAEA.MeCl solution 80% aqueous, 2.36 parts of a 53.45% aqueous acrylamide solution, 1.99 parts of an 80% aqueous DMAEA.BzCl solution, 0.8 parts of a solution that has 0.005 parts of VA-044 per part of solution, 0.4 parts of a solution of sodium ethylenediaminetetraacetate (EDTA) at 1% and 193.02 parts of deionized water are added to an appropriate glass vessel. The solution is sprayed with nitrogen gas for approximately 15 minutes at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp for about 1.5 hours. A clear 2% poly (20-DMAEA.MeCl / 20-DMAEA.BzCl / 60-AMD) solution having a standard viscosity of about 1.25 centipoise results.

EXAMPLE 23-41 The solubility behavior of the poly (20-DMAEA.MeCl / 20-DMAEA.BzCl / 60-AMD) terpolymer at 1% is determined as follows: 19 samples are prepared as shown in table 12 by mixing poly (20- DMAEA.MeCl / 20-DMAEA.BzCl / 60-AMD) at 2%, prepared as in Example S, with various amounts of sodium thiocyanate and ammonium sulfate. After mixing, the concentration of poly (20-DMAEA.MeCl / 20-DMAEA.BzCl / 60-AMD) is 1%, and the concentrations of sodium thiocyanate and ammonium sulfate in each sample are shown in Table 12. For each sample, the behavior of the polymer solubility (either soluble or precipitated) is visually determined at room temperature.

Table 12. Solubility of poly (20-DMAEA.MeCl / 20-DMAEA.BzCl / 60-AMD) at 1% as a function of the concentration of ammonium sulfate and sodium thiocyanate.

C- Comparative EXAMPLE 42 29. 06 Parts of a 52.21% aqueous acrylamide solution, 11.83 parts of DMAEA.MeCl, 13.5 parts of 20% dispersant prepared as in Example P, 13.5 parts of a 10% aqueous solution of a poly (vinylpyrrolidone-co- vinyl acetate) commercially available (having a reported molecular weight that is approximately 100,000), 14.4 parts of a 45% aqueous DIBSS solution (commercially obtained from Cytec Industries Inc., under the trade name IB-45®), 5.1 parts of a solution of sodium ethylenediaminetetraacetate (EDTA) at 1%, 65.7 parts of distilled water and 40.5 parts of ammonium sulfate are added to an appropriate container. The pH of the mixture is adjusted to 3.5 and the mixture is sprayed with nitrogen for 15 minutes. The mixture is heated to 4 ° C in a heating bath and 0.9 parts of a solution of AIBN (2,2'-azobis-2-methylpropionitrile) at 3.67% are added. The temperature of the reaction mixture is increased to 55 ° C during the course of one hour, then it is cooled to 45 ° C during the course of one hour, then it remains at this temperature for 2 hours as the temperature of the bath is maintained at 53 ° C.

The reaction mixture is filtered to remove the resultant granular polymer precipitate. The polymer is dried in a forced air oven at 105 ° C for three hours to produce substantially free-flowing polymer granules. The standard viscosity of polymer granules is 1.8 centipoise.

EXAMPLE 43 The clouding temperatures of the 0.5% poly (DMAEA.MeCl) as a function of% by weight of NaSCN and% by weight of (NH4) 2S0 are determined by preparing a series of samples, all of which contain 1.0 parts of a solution of 1% poly (DMAEM.MeCl) (prepared as in Example A, then diluted with deionized water), and various amounts of NaSCN, (NH4) 2S04, and water such that the final concentration of the poly (DMAEM, MeCl) is 0.5% in each sample and so that the final concentrations of the salts in each sample are as shown in Table 1 (Figure 1) . The cloudiness temperatures are determined by heating and stirring each sample to form a clear solution, then cooling until the solution becomes cloudy. The temperature of storing is the temperature at which turbidity is observed. The resulting clouding temperatures of the 0.5% poly (DMAEM.MeCl) as a function of% by weight of NaSCN and% by weight of (NH4) 2S04 are given in Table 1 (Figure 1).

EXAMPLE 44 The cloudiness temperatures of 5% poly (DMAEM.MeCl) as a function of% by weight of NaSCN and the type of cosmotropic salt are determined by preparing a series of samples, all of which contain 1.0 parts of a poly (DMAEM) solution. MeCl) at 10% (prepared as in Example A, then diluted with deionized water), and various amounts of NaSCN, water, and either (NH4) 2S04, Na2S04, Al2 (S04) 3 »18H20, such that The final concentration of the poly (DMAEM, MeCl) is 5% in each sample and so that the final concentrations of the salts in each sample are as shown in Table 2 (Figure 2). The cloudiness temperatures are determined by heating and stirring each sample to form a clear solution, then cooling the solution until it becomes cloudy. The cloudiness temperature is the temperature at which turbidity is observed. The resulting cloudiness temperatures of the 5% poly (DMAEM.MeCl) as a function of% by weight of NaSCN and the type of cosmotropic salt are given in Table 2 (Figure 2).

EXAMPLE 45 The clouding temperatures of the 0.5% poly (DMAEM.MeCl) as a function of the% by weight of chaotropic salt in (NH4) 2S04 are determined by preparing a series of samples, all of which contain 1.0 parts of a poly (DMAEM) solution. .MeCl) at 1% (prepared as in Example A, then diluted with deionized water), 0.4 parts (NH) 2S04, and various amounts of chaotropic salts (and anionic organic salts, in the case of sodium benzenesulfonate) such that the final concentration of poly (DMAEM, MeCl) is 0.5% in each sample, the final concentration of (NH) 2S0 is 20%, and so that the final concentrations of the chaotropic salts in each sample are as shown in Table 3 (Figure 3). The cloudiness temperatures are determined by heating and stirring each sample to form a clear solution, then cooling the solution until clouding is observed. The resulting clouding temperatures of the 0.5% poly (DMAEM.MeCl) as a function of the% by weight of chaotropic salt in 20% (NH4) 2S04 are given in Table 3 (Figure 3).

EXAMPLE T A solution of 20% poly (DMAEM.BzCl) is prepared as follows: 80 parts of a solution of 75% DMAEM.BzCl, 220 parts of deionized water and 0.060 parts of 2,2'-azobis dihydrochloride [2- (2-imidazdin-2-yl) propane], then VA-044, an azo initiator, are added to an appropriate vessel. The solution is sprayed with nitrogen gas and stirred for about one hour at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is thermally initiated by increasing the temperature of the solution to 44 ° C. Stirring and heating are continued for approximately 21 hours. The vessel is cooled to give a viscous, clear poly (DMAEM.BzCl) solution having a standard viscosity of about 1.3 centipoise.

EXAMPLE U A 20% poly (MAPTAC) solution is prepared as follows: 80% parts of a solution of 75% acrylamidopropyltrimethylammonium chloride (MAPTAC), 220 parts of deionized water and 0.060 parts of 2,2'-azobis [2- (2-imidazdin-2-yl) propane] dihydrochloride, Then VA-044, an azo initiator, is added to an appropriate container. The solution is sprayed with nitrogen gas and stirred for approximately one hour at room temperature. The nitrogen spray is changed to a nitrogen purge, and the polymerization is thermally initiated by increasing the temperature of the solution to 44 ° C. Stirring and heating are continued for approximately 21 hours. The vessel is cooled to give a viscous, clear poly (MAPTAC) solution having a standard viscosity of about 1.5 centipoise.

EXAMPLE V A 20% poly (DEAEM.MeCl) solution is prepared as follows: 80 parts of a 75% methacryloxyethyldiethymethyl ammonium chloride (DEAEM.MeCl) solution, 220 parts of deionized water and 0.015 parts of VA-044 are added to an appropriate glass container. The solution is sprayed with nitrogen gas and the solution is stirred for one hour at room temperature. The nitrogen mist is changed to a nitrogen purge, and the polymerization is initiated by exposing the glass container to an ultraviolet light lamp. Stirring and heating are continued for about 3 hours to give a viscous, clear poly (DEAEM.MeCl) solution having a standard viscosity of about 1.4 centipoise.

EXAMPLE 46 The cloudiness temperatures of 0.5% cationic polymers as a function of% by weight of NaSCN in 5% (NH4) 2S04 are determined by preparing a series of samples, which contain either 1.0 parts of a poly (DMAEM) solution. BzCl) at 1% (prepared as in Example T, then diluted with deionized water), 1.0 parts of a 1% poly (DEAEM.MeCl) solution (prepared as in Example V, then diluted with water deionized), 1.0 parts of a 1% poly (AMBTAC) solution (prepared as in Example G, then diluted with deionized water), 1.0 parts of a 1% poly (DMAEM.MeCl) solution (prepared as in Example A, then diluted with deionized water), 1.0 parts of a solution of poly (DMAEA. MeCl) at 1% (prepared as in Example H, then diluted with distilled water), or 1.0 parts of a 1% poly (MAPTAC) solution (prepared as in Example U, then diluted with deionized water) , 0.1 parts of (NH4) 2S04, water, and various amounts of NaSCN, such that the final concentration of the cationic polymer is 0.5% in each sample, the final concentration of (NH4) 2S04 is 5% in each sample, and so that the final NaSCN concentrations in each sample are as shown in Table 4 (Figure 4). The cloudiness temperatures are determined by heating and stirring each sample to form a clear solution, then until the solution becomes cloudy. The cloudiness temperature is the temperature at which turbidity is observed. The cloudiness temperatures of the cationic polymers at 0.5% as a function of% by weight of NaSCN in 5% (NH) 2S04 are shown in Table 4 (Figure 4).

EXAMPLE W A solution of 10% poly (AMD / DMAEA.MeCl / EA) is prepared as follows: 13.87 parts of 53.58% aqueous acrylamide (AMD), 25.31 parts of a solution of 80% aqueous ethacryloxyethyltrimethylammonium chloride (DMAEA.MeCl) %, 2.33 parts of ethyl acrylate (EA), 0.3 parts of EDTA, 258.16 parts of deionized water and 0.030 parts of VA-044 are added to an appropriate glass container. The solution is sprayed with nitrogen gas and stirred for about one hour at room temperature. The nitrogen mist is changed to a nitrogen purge, and the polymerization is initiated by increasing the temperature of the solution to 44 ° C. Stirring and heating are continued for about 21 hours to give a viscous, clear poly (AMD / DMAEA.MeCl / EA) solution having a standard viscosity of about 2.0 centipoise.

EXAMPLE 47 The clouding temperatures of 0.5% poly (DMAEA.MeCl) and 0.5% (45/45/10 mol) poly (AMD / DMAEA.MeCl / EA) as a function of% by weight of NaSCN in (NH4) ) 2S04 at 5% are determined by preparing a series of samples, which all contain either 1.0 parts of a 1% poly (DMAEA.MeCl) solution (prepared as in Example H, then diluted with deionized water), or 1.0 parts of a solution of poly (AMD / DMAEA.MeCl / EA) (45/45/10 mol%) at 1% (prepared as in Example W, then diluted with deionized water), water, 0.1 parts of (NH4) 2S04, and various amounts of NaSCN, such that the final concentration of the polymer is 0.5% in each sample, the final concentration of (NH4) 2S0 is 5% in each sample, and so that the final concentrations of the NaSCN in Each sample is as shown in Table 5 (Figure 5). The cloudiness temperatures are determined by heating and stirring each sample to form a clear solution, then cooling the solution until it becomes turbid. The cloudiness temperature is the temperature at which turbidity is observed. The resulting cloudiness temperatures of 0.5% poly (DMAEA.MeCl) and 0.5% (45/45/10 mole%) poly (AMD / DMAEA.MeCl / EA) as a function of% by weight of NaSCN in ( NH4) 2S04 at 5% are shown in Table 5 (Figure 5).

EXAMPLE 48 The clouding temperatures of poly (DMAEM.MeCl) and poly (DMAEM.DMS) at 0.5%, 5%, 15% and 20% as a function of% by weight of NaSCN in 5% (NH4) 2S04 are determined preparing a series of samples, which all contain either 1.0 parts of a 1%, 10%, 30% or 40% poly (DMAEM.MeCl) solution (prepared as in Example A, then diluted with deionized water ), or 1.0 parts of a 1%, 10%, 30% or 40% poly (DMAEM.DMS) solution (prepared as in Example I, then diluted with deionized water), 0.1 parts of (NH4) 2S04 , and various amounts of NaSCN and water, such that the final concentration of (NH4) 2S04 is 5% in each sample, and so that the final concentrations of the NaSCN and the polymer in each sample are as shown in Table 6 ( Figure 6). The cloudiness temperatures are determined by heating and stirring each sample to form a clear solution, then cooling the solution until it becomes turbid. The cloudiness temperature is the temperature at which turbidity is observed. The resulting clouding temperatures of poly (DMAEM, MeCl) and poly (DMAEM.DMS) at 0.5, 5%, 15% and 20% as a function of% by weight of NaSCN in 5% (NH4) 2S04 are shown in Table 6 (Figure 6).

EXAMPLE 49 The turbidity temperature of 0.5% (H 4 OEM.MeCl) in 20% (NH 4) 2 S0 and 4% Nal / NaBr mixture as a function of the weight fraction of Nal in a Nal / NaBr mixture is determined by preparing a series of samples, all of which contain 1.0 parts of a 1% poly (DMAEM.MeCl) solution (prepared as in Example A, then diluted with deionized water), 0.4 parts of (NH4) 2S04, and several amounts of Nal, NaBr, and water, such that the final concentration of the poly (DMAEM, MeCl) is 0.5% in each sample, the final concentration of (NH4) 2S04 is 20%, the final concentration of Nal and NaBr in each sample is a total of 4%, and the Nal weight fractions in the Nal / NaBr mixture are as shown in Table 7 (Figure 7). The cloudiness temperatures are determined by heating and stirring each sample to form a clear solution, then cooling the solution until it becomes cloudy. The cloudiness temperature is the temperature at which turbidity is observed. The resulting cloudiness temperatures of 0.5% poly (DMAEM.MeCl) in 20% (NH4) 2S04 and 4% Nal / NaBr mixture as a function of the weight fraction of Nal in the Nal / NaBr mixture are shown in Table 7 (Figure 7).

EXAMPLE 50 The clouding temperature of the 0.5% poly (DMAEM.MeCl) as a function of% by weight of anionic organic salt and% by weight of (NH4) 2S04 are determined by preparing a series of samples, all of which contain 1.0 part of a solution of 1% poly (DMAEM.MeCl) (prepared as in Example A, then diluted with deionized water), and various amounts of anionic organic salt, water, and either without (NH4) 2S04, such that the The final concentration of the poly (DMAEM .MeCl) is 0.5% in each sample and so that the final concentrations of the anionic organic salts in each sample are as shown in Table 8 and Figure 8 (without ammonium sulfate) and the Table 9 and Figure 9 (20% ammonium sulfate). The cloudiness temperatures are determined by heating and stirring each sample to form a clear solution, then cooling the solution until it becomes turbid. The cloudiness temperature is the temperature at which turbidity is observed. The resulting cloudiness temperatures of 0.5% poly (DMAEM.MeCl) as a function of% by weight of anionic organic salt and% by weight of (NH4) 2S04 are given in Tables 8 and 9 (Figures 8 and 9, respectively). In this example, all the anionic organic salts are anionic hydrotropic salts.

EXAMPLE 51 The clouding temperature of 0.5% (55/45 mol) poly (DMAEA.MeCl / AMD) as a function of% by weight of DIBSS and% by weight of (NH4) 2S04 is determined by preparing a series of samples, which all contain 1.0 parts of a 1% poly (DMAEA.MeCl / AMD) solution (prepared as in Example Q, then diluted with deionized water), either 0.1 or 0.3 parts of (NH) 2S04, and several amounts of DIBSS and water, such that the final concentration of the poly (DMAEA.MeCl / AMD) is 0.5% in each sample and so that the final concentrations of the salts in each sample are as shown in Table 10 (Figure 10). The cloudiness temperatures are determined by heating and stirring each sample to form a clear solution, then cooling the solution until it becomes turbid. The cloudiness temperature is the temperature at which turbidity is observed. The resulting clouding temperatures of the poly (DMAEA.MeCl / AMD) (55/45 mol%) at 0.5% as a function of the% by weight of DIBSS and the% by weight of (NH) 2S04 are shown in Table 10 ( Figure 10).

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (11)

1. A process, characterized in that it comprises mixing, in any order, water, at least one polymer soluble in cationic water, an effective amount of at least one cosmotropic salt, and an effective amount of at least one chaotropic salt, to form an aqueous composition that it comprises at least one precipitated cationic water-soluble polymer, wherein the chaotropic salt is present in an amount greater than 1%, by weight, based on the weight of the cationic water-soluble polymer.

2. A process, characterized in that it comprises polymerizing at least one cationic monomer in an aqueous solution composed of an effective amount of at least one chaotropic salt and an effective amount of at least one cosmotropic salt, to form an aqueous composition comprising at least one soluble polymer in precipitated cationic water.

3. A process, characterized in that it comprises mixing, in any order, water, at least one polymer soluble in cationic water, an effective amount of at least one cosmotropic salt, and an effective amount of at least one anionic organic salt, to form an aqueous composition comprising at least one precipitated cationic water soluble polymer.

4. A process, characterized in that it comprises polymerizing at least one cationic monomer in an aqueous solution composed of an effective amount of at least one anionic organic salt and an effective amount of at least one cosmotropic salt, to form an aqueous composition comprising at least one polymer soluble in precipitated cationic water.

5. A process according to claim 1, 2, 3 or 4, characterized in that a part or all of the precipitated cationic water-soluble polymer is precipitated as a polymer dispersion.

6. A process according to claim 1, 2, 3, 4 or 5, characterized in that the precipitated cationic water-soluble polymer contains recurring units having the formula where R, is either hydrogen or CH3, A is either an oxygen or NH atom, B is an alkylene or oxyalkylene group having 1 to 5 carbons, R2 and R3 are each an alkyl group having from 1 up to 3 carbons, R4 is either an alkyl or substituted alkyl group having from 1 to 10 carbons, or a substituted aryl or aryl group having from 6 to 10 carbons, and X is an anionic counterion.

7. A composition composed of water, at least one precipitated cationic water soluble polymer, an effective amount of at least one cosmotropic salt, and an effective amount of at least one chaotropic salt, characterized in that the chaotropic salt is present in an amount greater than 1. %, by weight, based on the weight of the polymer soluble in cationic water.

8. A composition, characterized in that it is composed of water, at least one polymer soluble in precipitated cationic water, an effective amount of at least one cosmotropic salt, and an effective amount of at least one anionic organic salt.

9. A composition according to claim 7 or 8, characterized in that the precipitated cationic water soluble polymer contains recurring units having the formula B Ri-lfjrBs where R, is either hydrogen or CH3, A is either an oxygen or NH atom, B is an alkylene or oxyalkylene group having 1 to 5 carbons, R2 and R3 are each an alkyl group having from 1 up to 3 carbons, R4 is either an alkyl or substituted alkyl group having from 1 to 10 carbons, or a substituted aryl or aryl group having from 6 to 10 carbons, and X is an anionic counterion.

10. A process for concentrating a dispersion of suspended solids, characterized in that it comprises the stripping of a dispersion of suspended solids by adding an effective amount of the composition of claim 7, 8 or 9 to the dispersion.

11. A soil conditioning process, characterized in that it comprises adding to the soil an amount for the conditioning of the soil of the composition of claim 7, 8 or 9.