CN105669899A - Novel non-phosphorus quadripolymer scale inhibitor and preparation method thereof - Google Patents

Abstract

The invention discloses a novel non-phosphorus quadripolymer scale inhibitor and a preparation method thereof.The novel non-phosphorus quadripolymer scale inhibitor is characterized by being formed by polymerization of four monomers including itaconic acid, methyl acrylate, acrylamide and 2-acrylamido-2-methylpropane sulfonic acid in an aqueous solution according to a mole ratio of 1:(0.4-0.6):(0.3-0.7):(0.1-0.4), wherein ammonium persulfate serves as an initiator.The prepared scale inhibitor is excellent in inhibition of calcium carbonate scale and calcium phosphate scale and has excellent iron oxide dispersing performance and non-phosphorus high-temperature-resistant performances.The novel non-phosphorus quadripolymer scale inhibitor can be widely applied to the field of industrial water treatment and is low in consumption, a manufacturing process is simple and free of pollution, and high economic benefits and environmental benefits are achieved.

Description

A novel phosphorus-free quaternary polymer scale inhibitor and preparation method thereof

technical field

The invention relates to a novel phosphorus-free quaternary polymer scale inhibitor and a preparation method thereof. The scale inhibitor is mainly used in the treatment of industrial circulating cooling water, and is a phosphorus-free, high-efficiency green scale inhibitor.

Background technique

Since the reform and opening up, with the rapid increase of my country's population and the continuous increase of per capita GDP, the problem of water supply and demand is constantly being intensified. Among them, industrial water is the first to face challenges, and most industrial sectors in my country have been using circulating cooling water systems. However, in the circulating cooling water system, due to the continuous heating and cooling of the circulating water, the concentration of metal ions in the water system increases, and then reaches a supersaturated state, or due to the increase in temperature, some metal salts form precipitation and deposit on the tubes. road, thus forming limescale. Scale will not only increase the flow resistance of water, slow down the flow speed, increase the operating cost of the circulating pump, but also affect the heat exchange efficiency of the heat exchanger. Dirt exists in the pipeline for a long time, which will cause subscale corrosion of the pipeline, and then cause more serious accidents, hindering the normal operation of the enterprise. Therefore, seeking a treatment method for scale has attracted the attention of researchers. One of the most widely used is the polymer antiscalant.

The development of scale inhibitors has played a key role in improving the utilization rate of industrial circulating water. Since the 1960s, scale inhibitors began to be developed. At that time, the scale inhibitors and dispersants used were mainly sodium lignosulfonate, etc., which had a certain scale inhibition effect and could partially solve the problems of scale deposition and zinc salt stability. But it is far from meeting the requirements of production for scale inhibition performance. For this reason, polymer scale inhibitors have been gradually developed, and the most widely used ones are phosphorus-containing polymer scale inhibitors. For example, the Chinese patent discloses that the application number is CN00113316 "a phosphorus-containing sulfonate copolymer and its preparation method and application", the application number is CN95111773 "a phosphorus-containing terpolymer water scale inhibitor", and the application number is It is the preparation method of CN03122759 containing ether phosphonic acid sulfonic acid multi-component copolymer and multifunctional water treatment agent ". But phosphorus can cause eutrophication of water body, destroy environment, with the limitation of environment to industrial sewage discharge and people's environmental protection awareness in the 1980s The enhancement of scale inhibitors is also developing towards non-toxic, harmless, phosphorus-free and environment-friendly scale inhibitors. At the beginning of research, there are mainly polyaspartic acid and polyepoxysuccinic acid, such as the Chinese patent application The number is CN02111415 "preparation method of environment-friendly antiscalant polyaspartic acid", and the application number is CN00310101837: "a kind of corrosion and scale inhibition treatment method containing polyepoxy succinic acid". But its cost is all too high, and the enterprise application Rarely. The polycarboxylate scale inhibitor currently researched is not only low in cost, but also does not cause phosphorus pollution, and has good scale inhibition performance, so it is widely used by enterprises. Polycarboxylate scale inhibitor is a carboxyl, Polymers with multiple functional groups such as lipid groups, sulfonic acid groups, and amido groups. After investigating the research and development of polycarboxylic acid scale inhibitors at home and abroad, the present invention has continuously summed up experience and developed a new water-soluble phosphorus-free Quaternary copolymer antiscalant.

Contents of the invention

The invention aims at a novel quaternary polymer scale inhibitor which is non-phosphorus and environmentally friendly, and has excellent scale inhibition performance on both calcium carbonate scale and calcium phosphate scale, and a preparation method thereof.

The purpose of the present invention can be achieved through the following measures:

A novel phosphorus-free quaternary polymer scale inhibitor is characterized in that the novel phosphorus-free polymer scale inhibitor is formed by free radical polymerization of four monomers A, B, C, and D in an aqueous solution. Copolymerized oligomers, of which:

A: itaconic acid

B: methyl acrylate

C: Acrylamide

D: 2-acrylamido-2-methylpropanesulfonic acid

The molar ratio of the four monomers A, B, C, and D is A:B:C:D=1:(0.4-0.6):(0.3-0.7):(0.1-0.4)

The preparation method of the above-mentioned novel phosphorus-free quaternary polymer scale inhibitor, the steps are:

(1) On a mass basis, dissolve 2-6g of acrylamide with an appropriate amount of deionized water to form an aqueous solution with a mass percentage of 10-20%, mix it with 3mL-6mL of methyl acrylate, and name it solution a; 2g-5g of ammonium sulfate is dissolved with an appropriate amount of deionized water to form an aqueous solution with a mass percentage of 10-15%, which is named solution b.

(2) Dissolve 9g of itaconic acid, 2-6g of acrylamide, and 3-8g of 2-acrylamido-2-methylpropanesulfonic acid with an appropriate amount of deionized water to form a mass percentage of 30-50 % aqueous solution, join in the four-necked flask, be warmed up to 45-75 ℃, add isopropanol under stirring, then solution a and solution b are put into dropping funnel respectively and drop at a constant speed (dropping time is 30- 45min), after the dropwise addition, the temperature was raised to 75-95°C. Keep it warm for 1-6 hours, and after cooling, adjust the pH to 7-8 with 30% sodium hydroxide solution to obtain a new type of non-phosphorus quaternary polymer scale inhibitor.

According to the preparation method of the novel phosphorus-free tetrapolymer scale inhibitor according to claim 4, it is characterized in that the polymerization temperature is 75-95°C.

The beneficial effects of the present invention are:

Studies have shown that a variety of functional groups in the polymer can play a good anti-scaling effect. Among them, the carboxylic acid functional group is negatively charged after hydrolysis, has strong adsorption performance, and plays a major role in the scale inhibition performance of calcium carbonate scale, while the sulfonic acid functional group is very soluble in water, and its acidity is higher than that of the carboxylic acid functional group. Therefore, its adsorption performance on crystals is low, resulting in the fact that the scale inhibition effect of sulfonic _acid functional groups on CaCO3 is not as good as that of carboxyl functional groups. However, the sulfonic acid functional group has good resistance to temperature and salt, is suitable for water systems with high salinity, and can improve the dispersion performance of Fe ₂ O ₃ . Ester groups and amide groups also have adsorption properties, and they can be adsorbed on the surface of inorganic salt microcrystals, which can also hinder the growth of microcrystals and destroy the internal structure of microcrystals.

The polymerized monomer itaconic acid used in the present invention is a kind of unsaturated dicarboxylic acid, which is mostly produced by starch fermentation, has simple process, lower production cost than similar chemical products, and is non-toxic and easy to degrade. The molecule of 2-acrylamido-2-methylpropanesulfonic acid contains not only amide groups but also strong hydrophilic sulfonic acid groups. The amide groups can prevent the copolymer from gel polymerization, while the sulfonic acid groups The strong charge density will make the monomer have good adsorption and complexation, and the sulfonic acid group will also strengthen the rigidity of the polymer molecular chain and improve the thermal stability of the polymer. Therefore, the new phosphorus-free copolymer scale inhibitor has good ability to inhibit calcium carbonate scale, calcium phosphate and disperse iron oxide, and has the characteristics of high thermal stability and phosphorus-free.

The polymer has simple synthesis process and low production cost, can be used for the treatment of industrial circulating cooling water, and is an efficient green scale inhibitor.

detailed description

Example 1

Dissolve 2.7g of acrylamide in 30ml of water and mix it with 2.5ml of methyl acrylate to make solution a; dissolve 2.0g of ammonium persulfate in 20ml of water to make solution b.

6g of itaconic acid, 5.1g of 2-acrylamido-2-methylpropanesulfonic acid were dissolved in 120ml of water and then added to a four-necked flask equipped with a thermometer, a condenser tube and a constant pressure titration funnel, and the temperature was increased Stir at 50°C, add a certain amount of isopropanol (5%wt), and then titrate solution a and solution b at a constant speed through a constant pressure funnel, the time for adding drops is 30min, and after the addition, raise the temperature to 85°C , react at constant temperature with nitrogen for 3 hours, cool down, adjust the pH to 7-8 with 30% sodium hydroxide solution, and remember to get a light yellow transparent liquid, which is a new type of phosphorus-free quaternary polymer scale inhibitor.

Example 2

Dissolve 1.8g of acrylamide in 20ml of water and mix it with 2.5ml of methyl acrylate to make solution a; dissolve 1.5g of ammonium persulfate in 20ml of water to make solution b.

8.2g of itaconic acid, 2.6g of 2-acrylamido-2-methylpropanesulfonic acid were dissolved in 100ml water and then added to a four-necked flask equipped with a thermometer, a condenser tube and a constant pressure titration funnel. Stir the temperature to 60°C, add a certain amount of isopropanol (5%wt), and then titrate solution a and solution b at a constant speed through a constant pressure funnel. ℃, nitrogen constant temperature reaction for 3.5 hours, cooling, adjust the pH to 7-8 with 30% sodium hydroxide solution, remember to get a light yellow transparent liquid, which is a new type of non-phosphorus quaternary polymer scale inhibitor.

Example 3

Dissolve 0.8g of acrylamide in 10ml of water and mix it with 2.5ml of methyl acrylate to make solution a; dissolve 1.5g of ammonium persulfate in 20ml of water to make solution b.

9.8g of itaconic acid, 2.6g of 2-acrylamido-2-methylpropanesulfonic acid were dissolved in 130ml of water and then added to a four-necked flask equipped with a thermometer, a condenser tube and a constant pressure titration funnel. Stir the temperature to 60°C, add a certain amount of isopropanol (5%wt), and then uniformly titrate solution a and solution b therein through a constant pressure funnel, the time of dropping is 40min, and the temperature is raised to 70 ℃, react at constant temperature with nitrogen for 4 hours, cool down, adjust the pH to 7-8 with 30% sodium hydroxide solution, and remember to get a light yellow transparent liquid, which is a new type of non-phosphorus quaternary polymer scale inhibitor.

Example 4

Dissolve 2.7g of acrylamide in 30ml of water and mix it with 2.5ml of methyl acrylate to make solution a; dissolve 3.0g of ammonium persulfate in 20ml of water to make solution b.

11g of itaconic acid, 7.8g of 2-acrylamido-2-methylpropanesulfonic acid were dissolved in 200ml of water and then added to a four-necked flask equipped with a thermometer, a condenser tube and a constant pressure titration funnel, and the temperature was increased Stir at 50°C, add a certain amount of isopropanol (5%wt), and then titrate solution a and solution b at a constant speed through a constant pressure funnel, the time for adding drops is 1h, and after the addition is completed, raise the temperature to 85°C , react at constant temperature with nitrogen for 4 hours, cool down, adjust the pH to 7-8 with 30% sodium hydroxide solution, and remember to get a light yellow transparent liquid, which is a new type of phosphorus-free quaternary polymer scale inhibitor.

Example 5

Dissolve 1.8g of acrylamide in 20ml of water and mix it with 2.5ml of methyl acrylate to make solution a; dissolve 3.5g of ammonium persulfate in 30ml of water to make solution b.

9.8g of itaconic acid, 7.8g of 2-acrylamido-2-methylpropanesulfonic acid were dissolved in 180ml of water and then added to a four-necked flask equipped with a thermometer, a condenser tube and a constant pressure titration funnel. Stir at 40°C, add a certain amount of isopropanol (5%wt), and then titrate solution a and solution b at a constant speed through a constant pressure funnel. ℃, constant temperature reaction with nitrogen for 4.5 hours, cooling, adjust the pH to 7-8 with 30% sodium hydroxide solution, and remember to get a light yellow transparent liquid, which is a new type of non-phosphorus quaternary polymer scale inhibitor.

Example 6

In an embodiment, the assay method of calcium carbonate scale inhibition rate, calcium phosphate scale inhibition rate and iron trioxide ability is as follows:

Determination of scale inhibition rate of calcium carbonate and calcium phosphate

The static scale inhibition performance test method of calcium carbonate and calcium phosphate is determined according to GB/T16632-2008 and GB/T22626-2008. The experimental conditions for the scale inhibition of calcium carbonate are: the concentrations of Ca ²⁺ and HCO ^3- are both 250mg/ L, pH=7-9, the temperature is 80°C, the time is 10h; the scale inhibition test conditions of calcium phosphate are: the concentration of Ca ²⁺ is 250mg/L, the concentration of PO ₄ ^3- is 5mg/L, and the temperature is 80 ℃, the time is 10h, and the scale inhibition performance is shown in Table 1.

Determination of Dispersion Properties of Iron Oxide

Prepare the solution with FeSO ₄ 7H ₂ O and CaCl ₂ so that the concentration of Ca ²⁺ is 160mg/L, the concentration of Fe ²⁺ is 10mg/L, adjust the pH to 9 with boric acid solution, and then add a certain amount of polymer scale inhibitor agent, magnetically stirred for 15 minutes, let stand, kept at 50°C for 5 hours, cooled, and measured its light transmittance T% at 420nm with a spectrophotometer.

Calcium carbonate scale inhibition rate of the embodiment of table 1, calcium phosphate scale inhibition rate and the determination result of iron trioxide ability

As can be seen from Table 1, this invention selects the novel phosphorus-free quaternary polymer scale inhibitor that the monomer itaconic acid, methyl acrylate, acrylamide, 2-acrylamido-2-methyl propane sulfonic acid is polymerized in When the dosage is 30mg/L, it has a good scale inhibition effect on calcium carbonate, and the scale inhibition rate is above 98%. At the same time, it also has good scale inhibition performance on calcium phosphate scale, and has strong iron oxide dispersion. ability.

Claims (5)

1. a novel non-phosphate quadripolymer Scale inhibitors, it is characterised in that, described novel non-phosphate quadripolymer Scale inhibitors is the oligopolymer become by Raolical polymerizable copolymerization in aqueous by A, B, C, D tetra-kinds of monomers, wherein:

A: methylene-succinic acid

B: methyl acrylate

C: acrylamide

D:2-acrylamido-2-methyl propane sulfonic acid

The mol ratio of A, B, C, D tetra-kinds of monomers is A:B:C:D=1:(0.4-0.6): (0.3-0.7): (0.1-0.4).

2. require described novel non-phosphate quadripolymer Scale inhibitors according to right 1, it is characterised in that copolymerization of carboxyl, ester group, amide group, these four kinds of officials of sulfonic group being reunited, thus possess efficient scale-inhibiting properties.

3. require described novel quadripolymer Scale inhibitors according to right 1, it is characterised in that, the initiator adopted during four kinds of monomer generation Raolical polymerizables is water-soluble ammonium persulphate.

4. requiring described novel non-phosphate quadripolymer Scale inhibitors preparation method according to right 1, step is:

(1) in mass, the acrylamide of 2-6g is made into, with appropriate deionized water dissolving, the aqueous solution that mass percent is 10-20%, mixes with the methyl acrylate of 3mL-6mL, called after solution a; By ammonium persulphate 2g-5g, it is made into the aqueous solution called after solution b of mass percent 10-15% with appropriate deionized water dissolving.

(2) by the methylene-succinic acid of 7-9g, 2-acrylamido-2-the methyl propane sulfonic acid of 3-8g is with appropriate deionized water dissolving, it is made into the aqueous solution that mass percent is 30-50%, join in four mouthfuls of flasks, it is warming up to 45-75 DEG C, under agitation add Virahol, then solution a and solution b is put into respectively dropping funnel and adds at the uniform velocity to drip (drip and add the time as 30-45min), after dropwising, be warming up to 75-95 DEG C. It is incubated 1-6 hour, regulates pH to 7-8 with the sodium hydroxide solution of 30% after cooling, obtain novel non-phosphate quadripolymer Scale inhibitors.

5. the preparation method of novel non-phosphate quadripolymer Scale inhibitors according to right 4, it is characterised in that polymerization temperature is 75-95 DEG C.