CN118987704A

CN118987704A - Powdery non-silicon type foam inhibitor and preparation method thereof

Info

Publication number: CN118987704A
Application number: CN202411400572.9A
Authority: CN
Inventors: 杨柏忠; 杨颖超
Original assignee: JIANGSU SAIOUXINYUE DEFOAMER CO Ltd
Current assignee: JIANGSU SAIOUXINYUE DEFOAMER CO Ltd
Priority date: 2024-10-09
Filing date: 2024-10-09
Publication date: 2024-11-22

Abstract

The invention discloses a powdery non-silicon type foam inhibitor and a preparation method thereof. The foam inhibitor comprises polyether, white carbon black, ethylene bis stearamide and modified grease, wherein the modified grease is prepared from a grafting agent, natural grease, a modifying agent, an oxidizing agent and a catalyst. The ester bond in the natural grease is alcoholyzed by utilizing the alcoholic hydroxyl of the grafting agent, the modifier is oxidized into peroxy acid by the oxidant, and then the peroxy acid reacts with the double bond in the natural grease to prepare the modified grease, which is compounded with polyether, white carbon black and ethylene bis stearamide to obtain the foam inhibitor. The foam inhibitor prepared by the invention has good foam inhibition effect and good stability.

Description

Powdery non-silicon type foam inhibitor and preparation method thereof

Technical Field

The invention relates to the technical field of suds suppressors, in particular to a powdery non-silicon suds suppressors and a preparation method thereof.

Background

Suds suppressors are chemical substances capable of reducing the formation of bubbles. The main action mechanism is to form a film on the surface of the liquid, and the formation and aggregation of bubbles are hindered by reducing the tension of the surface of the liquid. The film can effectively prevent the generation of bubbles, and the surface of the liquid is kept flat and stable. The field of application of suds suppressors is very broad and covers almost all industrial processes where foam generation needs to be controlled. For example, suds suppressors have been shown to play an irreplaceable role in the industries of chemical manufacturing, pharmaceutical technology, food processing, water-based paint, water-based ink, water-based adhesive, and water-based cleaning agent. Suds suppressors are of a wide variety and vary in composition. Common suds suppressors consist essentially of water-based or aqueous emulsion-based and oil-based compositions having different chemical properties and suds suppressing effects.

The powdery non-silicon foam inhibitor is a chemical auxiliary agent widely applied in various processes and mainly used for reducing or eliminating foam generation in a liquid system. Such suds suppressors are free of silicon components and therefore have unique advantages in certain specific applications, such as those involving systems that are sensitive to silicon. During the manufacturing process, powdered non-silicone suds suppressors typically comprise a variety of active ingredients, such as organic esters, special polymers, dispersants, etc., which are carefully designed and selected to ensure high suds suppressors efficiency and stability. By a specific preparation process, the components are uniformly mixed to form a powdery final product, and the powder is easy to disperse and apply in various liquid systems.

CN102302869a discloses a solid particle foam inhibitor and its preparation method, the foam inhibitor component includes 50-80% of organic carrier, 10-18% of main defoaming material, 0.5-4% of emulsifying agent, 1-10% of structuring agent and 3-25% of deionized water. The preparation method of the foam inhibitor comprises the steps of fully mixing main defoaming substances and emulsifying agents, adsorbing the mixture on a carrier, adding a structural agent, and granulating and drying to form particles with good fluidity. The solid particle foam inhibitor prepared by the method has good application in the processes of cleaning, sewage treatment and textile printing and dyeing industry. However, the defoamer prepared by the method is adsorbed on the carrier in an adsorption mode after being mixed with the emulsifier, and the adsorption mode easily influences the stability of the defoamer, so that the foam inhibition effect of the defoamer is influenced.

CN103920312B discloses a preparation method of foam inhibitor and defoamer special for organosilicon wetting agent, which comprises 50-70 parts of foam inhibitor, 10-30 parts of silicone paste foam breaker and 20-30 parts of polyether modified silicone oil low-foam emulsifier. The foam inhibitor prepared by the method can effectively emulsify the polyoxypropylene ether modified low-polysiloxane foam inhibitor into emulsion which is stable in water, does not influence the surface tension and expansion capacity of the organosilicon wetting agent, has a certain foam breaking capacity, and can break formed foam. However, with the use of oligosiloxanes, they are poorly soluble in water, which leads to difficulties in their dispersion in aqueous systems. To solve this problem, it is often necessary to add a dispersant, but too much dispersant may affect the stability of the emulsion and the defoaming and foam suppressing effects.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention aims to improve the defoaming effect and stability of the powdery non-silicon type suds suppressors and to prolong the storage time.

In order to achieve the above purpose, the invention provides a powdery non-silicon type foam inhibitor and a preparation method thereof, comprising the following steps: polyether, white carbon black, ethylene bis stearamide and modified grease, wherein the modified grease is prepared from a grafting agent, natural grease, a modifying agent, an oxidizing agent and a catalyst.

Preferably, the preparation method of the modified grease comprises the following steps:

Stirring a grafting agent, natural oil and fat and an alkaline catalyst for 2-6 hours at 40-65 ℃, then carrying out normal pressure distillation to recover excessive grafting agent, standing for 1-2 hours to remove an oil layer, and washing with water to remove the alkaline catalyst and the natural oil and fat to obtain a mixture;

step two, adding the mixture in the step one into a modifier and an acid catalyst, heating to 40-65 ℃, dropwise adding an oxidant, and stirring for 2-6 hours to obtain an oil-water mixed solution;

And thirdly, filtering the oil-water mixed solution obtained in the second step to obtain an upper layer oil layer, washing with 50-60 ℃ water for 1-2 times, neutralizing with 2-5wt% sodium hydroxide aqueous solution, washing with 50-60 ℃ water for 2-3 times until the pH value is neutral, and then distilling under reduced pressure to remove the solvent and low-boiling impurities to obtain the modified oil.

More preferably, the preparation method of the modified grease comprises the following steps in parts by weight:

Stirring 60-85 parts of grafting agent, 80-120 parts of natural grease and 0.5-2 parts of alkaline catalyst at 40-65 ℃ for 2-6 hours, then carrying out normal pressure distillation to recover excessive grafting agent, then standing for 1-2 hours to remove an oil layer, and washing with water to remove the alkaline catalyst and the natural grease to obtain a mixture;

Step two, adding 20-40 parts of modifier and 0.1-1 part of acid catalyst into the mixture obtained in the step one, mixing, heating to 40-65 ℃, dropwise adding oxidant, and stirring for 2-6 hours to obtain an oil-water mixed solution;

And thirdly, filtering the oil-water mixed solution obtained in the second step to obtain an upper layer oil layer, washing with 50-60 ℃ water for 1-2 times, neutralizing with 2-5% sodium hydroxide aqueous solution, washing with 50-60 ℃ water for 2-3 times until the pH value is neutral, and then distilling under reduced pressure to remove the solvent and low-boiling impurities to obtain the modified oil.

Preferably, the modifier is any one of m-methylbenzoic acid, succinic acid and 5,5,6,6,7,7,8,8,8-nonafluoro-2-methylene octanoic acid.

More preferably, the modifier is 5,5,6,6,7,7,8,8,8-nonafluoro-2-methyleneoctanoic acid.

Preferably, the grafting agent is any one of trimethylolpropane, triphenylmethanol and (3E) -1-amino-3-penten-2-ol.

Preferably, the oxidant is hydrogen peroxide.

Preferably, the natural oil is corn oil.

Preferably, the acidic catalyst is concentrated sulfuric acid.

The preparation method of the powdery non-silicon type foam inhibitor comprises the following steps of:

S1, stirring 20-35 parts of modified grease, 20-40 parts of polyether and 0.1-1 part of acid catalyst at 120-150 ℃ for 4-8 hours to obtain polyether modified grease;

And S2, uniformly stirring the polyether modified grease in the S1, 5-10 parts of white carbon black and 1-7 parts of ethylene bis stearamide at the temperature of 90-120 ℃, and drying and crushing to obtain the powdery non-silicon foam inhibitor.

In this formulation, the raw materials and their actions are as follows:

polyether: polyether can react with modified grease under the action of an acid catalyst to obtain polyether modified grease. Polyethers are a class of highly effective foam inhibitors and defoamers that are capable of effectively inhibiting or eliminating foam by reducing the surface tension of the liquid and disrupting the stability of the foam. The special molecular structure of polyether makes it possible to form one film on the surface of liquid to prevent foam from forming and expanding. The inclusion of polyethers can improve the dispersibility and stability of suds suppressors in the system. Because the polyether has good compatibility and wettability, the polyether can be better mixed with white carbon black and ethylene bis stearamide and uniformly distributed in a system, so that the foam inhibitor can continuously and effectively play a role.

White carbon black: the white carbon black has a huge specific surface area and a three-dimensional network structure, and can adsorb and impact bubbles to cause weak points of the bubbles. Under the effect of the low surface tension of the silicone oil, these weak points break, helping to eliminate the foam. The white carbon black is used as one of the components of the foam inhibitor, so that the consistency of the system can be improved, and the phenomenon of precipitation or layering of the foam inhibitor in the use process is prevented. This helps to maintain stability and durability of the suds suppressor.

Ethylene bis stearamide: ethylene bis stearamide is a defoaming active substance with the ability to reduce the surface tension of liquids. Ethylene bis stearamide helps to break down the stability of the foam by reducing the surface tension, making the foam easier to break and dissipate.

Grafting agent: the grafting agent is of a polyol structure, natural grease contains rich ester bonds, and under the action of an alkaline catalyst, the fatting bonds can be subjected to alcoholysis reaction with the grafting agent to obtain glyceride and fatty acid compounds, wherein the glyceride and the fatty acid compounds are common substances in the foam inhibitor. Meanwhile, the generated alcoholysis grease contains a large number of double bonds, and the hydrophilicity and the diffusivity of the grease can be improved by epoxidation of the double bonds into epoxy bonds, so that the foam eliminating and inhibiting performance of the grease can be improved. The grafting agent in the invention selects trimethylolpropane, triphenylmethanol and (3E) -1-amino-3-pentene-2-alcohol.

(3E) -1-amino-3-penten-2-ol contains amino (-NH 2), unsaturated double bond (-c=c-) and hydroxyl (-OH), these three functional groups providing various chemical reaction pathways and higher chemical activity. The amino group can form a stronger hydrogen bond with water molecules due to the polarity of the amino group, so that a stable monomolecular layer can be formed at a liquid interface, the surface tension is effectively reduced, and the defoaming process is accelerated. The unsaturated double bond provides additional chemical reaction points, promotes diversified reactions with other matrixes, enhances intermolecular crosslinking, and improves the mechanical strength and stability of the product. The hydroxyl groups can also form hydrogen bonds with water molecules, so that the grafting agent can be better dispersed in a water-based medium and can be uniformly combined with other materials, and the defoaming effect is improved. In addition, (3E) -1-amino-3-pentene-2-ol interacts with molecules on the surfaces of water and bubbles through hydrogen bonds and Van der Waals forces to quickly reduce the surface tension of the bubbles and promote bubble combination and collapse, and the multipoint binding sites (amino, double bonds and hydroxyl groups) provided by the (3E) -1-amino-3-pentene-2-ol obviously improve the bubble breaking speed and the capability of preventing generation of new bubbles.

The trimethylolpropane has stronger water solubility and multi-point interaction capability with water due to the fact that the trimethylolpropane contains three hydroxyl groups, so that the trimethylolpropane has certain advantages in the aspects of breaking bubbles and preventing generation of new bubbles. These hydroxyl groups help to reduce the surface tension by forming hydrogen bonds between water molecules, thereby promoting rapid collapse of the bubbles. However, trimethylolpropane is insufficient in chemical reactivity and interfacial activity to achieve an optimal defoaming effect due to the lack of an amino group, which is a functional group having higher polarity and activity. Particularly in environments where rapid reactions are required and chemical stability is high, it does not behave as well as those grafting agents containing amino groups or other reactive functional groups.

The triphenylmethanol provides certain rigidity and structural stability through the benzene ring contained in the triphenylmethanol, and the structural characteristic is helpful for improving the thermal stability and mechanical strength of the material, promoting the foam breaking speed to a certain extent and preventing the generation of new foam. The rigidity and larger planar structure of the benzene ring helps to break up the surface layer of the foam, thereby promoting bubble collapse. However, the macromolecular structure and the weaker polarity of triphenylmethanol create limitations in its dispersibility and activity in aqueous media, which is particularly pronounced in water-based systems. The benzene ring in the molecule has poor dispersibility and limited interaction capability with water molecules due to strong hydrophobicity, thereby affecting the overall defoaming efficiency.

In conclusion, while trimethylolpropane and triphenylmethanol exert an antifoaming effect under specific conditions, they are markedly inferior to grafting agents (3E) -1-amino-3-penten-2-ol containing more functional groups in terms of efficient antifoaming and foam suppressing properties due to the lack of highly polar and chemically active functional groups and the problem of dispersibility of their molecular structures in aqueous media.

In addition, methanol is an alcohol compound as a base, containing only one hydroxyl group (-OH). In chemical reactions, it acts primarily through this hydroxyl group. However, since the methanol structure is relatively simple, its functionality and reactivity are relatively low, especially when complex or high performance grafting reactions are required. Thus, in the present invention, methanol is not selected as the grafting agent.

Natural oil: natural oils and fats contain abundant glycerol ester bonds and double bonds. The natural oil is used as the initial raw material of the modified oil, and provides a base oil phase for the whole reaction system. In the preparation process of the modified grease, the grafting agent can be subjected to alcoholysis reaction with natural grease to form glyceride with a specific structure, and can also be subjected to reaction with the modifying agent under the action of an oxidant and a catalyst to obtain the modified grease. And then the modified grease is reacted with polyether, so that the foam inhibition performance of the grease can be improved, and the grease can be better adapted to the requirements of different application occasions.

Alkaline catalyst: the natural oil and fat and the grafting agent generate glyceride and fatty acid compounds under the catalysis of acidity or alkalinity, but the reaction speed of the acid catalyst is much slower than that of the alkalinity catalyst, and equipment is easy to corrode by the acid catalyst, so the alkalinity catalyst is used.

And (3) a modifier: the modifier contains carboxyl functional groups, can be oxidized into a peroxyacid compound under the action of an oxidant, and then reacts with unsaturated double bonds in the natural oil, so that the modified oil is prepared. The modifier of the invention selects m-methylbenzoic acid, succinic acid and 5,5,6,6,7,7,8,8,8-nonafluoro-2-methylene octanoic acid.

The molecular structure of m-methylbenzoic acid comprises a benzene ring and a carboxyl (-COOH) group on a side chain, which imparts unique chemical and physical properties to the compound. The benzene ring, as a typical aromatic ring structure, provides rigidity and hydrophobicity to the molecule, which makes the dispersibility of m-methylbenzoic acid in aqueous media somewhat limited. The hydrophobicity of the benzene ring and the greater pi-pi stacking tendency may cause aggregation in water, reducing its effectiveness. In addition, while carboxyl groups provide some polarity, which can theoretically enhance their solubility in water by forming hydrogen bonds to interact with water molecules, such effect is often insufficient to overcome the overall hydrophobicity imparted by benzene rings. Thus, while the benzene ring structure of m-methylbenzoic acid is advantageous in increasing molecular rigidity and providing a degree of chemical stability, its pronounced hydrophobic character and limited polar carboxyl groups limit its efficacy in aqueous media, which may affect the effectiveness of suds suppressors in practical applications.

Succinic acid is a linear dicarboxylic acid with two carboxyl groups (-COOH) at both ends of the molecule, imparting significant chemical activity and polarity characteristics to succinic acid. In the use of suds suppressors, the dicarboxylic functional groups of succinic acid are critical because they can be oxidized in the presence of an oxidizing agent (e.g., hydrogen peroxide) to form peroxides which can effectively react with the unsaturated double bonds in the natural oils to form epoxides. This reaction not only improves the polarity of the oil, increases its dispersibility in aqueous media, but also increases the overall reactivity of the oil, thereby enhancing the efficacy of the suds suppressors. However, the linear structure of succinic acid, while providing chemical stability and predictable reaction behavior in some respects, in comparison to fluorine-containing modifiers lacks the low hydrophobicity and extremely low surface tension characteristic of fluorine compounds, which is not as good as fluorine-containing modifiers in rapidly breaking foam films. Thus, while succinic acid plays a role in increasing the polarity of grease and improving dispersibility through its carboxyl group, it is inferior to a fluorine-containing modifier specifically designed in its ability to rapidly lower interfacial tension and destroy foam structure.

5,5,6,6,7,7,8,8,8-Nonafluoro-2-methyleneoctanoic acid is a fluorinated compound with a unique structure, and molecules of the compound not only contain polar carboxyl (-COOH) but also introduce a plurality of fluorine atoms (-F). These fluorine atoms impart excellent hydrophobicity and exceptionally low surface tension to the compound, which greatly enhances its wetting and penetration capabilities chemically, allowing it to spread rapidly over the surface of the bubbles, effectively destroying the foam structure. In addition, the carboxyl can be oxidized under the combined action of a catalyst and an oxidant such as hydrogen peroxide to form peroxide with stronger activity, and the peroxide reacts with unsaturated double bonds in the natural grease to promote the epoxidation reaction to generate epoxide. The epoxide not only improves the polarity of grease, so that the dispersibility and stability of the modified grease in an aqueous medium are obviously improved, but also the overall efficiency of the surfactant in the whole foam inhibitor formula is increased.

Formic acid is a very simple structure carboxylic acid, the molecule contains only one carboxyl group (-COOH), making it relatively limited in its function in chemical reactions. As a modifier, formic acid can indeed be oxidized in the presence of an oxidizing agent such as hydrogen peroxide to form peroxides which can react further with unsaturated double bonds in the grease, helping to increase the polarity of the grease and improve its dispersibility in aqueous media. However, the single carboxyl group of formic acid has been limited in improving the reactivity of the modified grease and enhancing the properties of the final product as compared with other modifiers having more functional groups. This is mainly because the small molecular structure of formic acid is not sufficient to introduce sufficient chemical diversity or provide stable chemical linkages during modification, and its single functional group also limits the complexity and efficiency of interactions with other molecules. Therefore, in the present invention, a modifier having higher functionality is selected to achieve more excellent foam suppressing and defoaming effects, without using formic acid.

Acid catalyst: in the process of preparing the modified grease, the oxidant oxidizes the modifier into the peroxyacid under the action of the acid catalyst, and the process is a reversible reaction, is slower to perform, and is beneficial to the formation of the peroxyacid by adding the strong acid for catalysis. The modifier is capable of introducing new functional groups or structures, thereby imparting new properties or characteristics to the natural oils.

Oxidizing agent: in the preparation process of the modified grease, the oxidant oxidizes the modifier into a peroxy acid compound, and then the peroxy acid compound reacts with double bonds in the natural grease in an addition way, and the modified grease with specific structure and performance can be prepared through the action of the oxidant.

The invention has the beneficial effects that:

Compared with the prior art, the method has the advantages that the ester bonds in the natural oil are alcoholyzed by utilizing the alcoholic hydroxyl groups of the grafting agent; and then oxidizing carboxyl in the modifier into a peroxy acid compound under the action of an oxidant, and then reacting with double bonds in the natural oil to prepare the modified oil. And reacting the prepared modified grease with polyether to prepare polyether modified grease, and finally compounding the polyether modified grease with white carbon black and ethylene bis stearamide to prepare the foam inhibitor, wherein the foam inhibition effect and stability of the foam inhibitor are enhanced by modifying epoxy groups contained in the natural grease.

Detailed Description

Parameters of specific chemicals are used, sources.

(3E) -1-amino-3-penten-2-ol, 3-penten-2-ol, 1-amino-, (3 e) -, CAS No.: 112069-72-4.

5,5,6,6,7,7,8,8,8-Nonafluoro-2-methyleneoctanoic acid, 5,5,6,6,7,7,8,8,8-nonafluoro-2-methyleneoctanoic acid, CAS number: 36390-11-1.

Polyether, model: 330N, sandy chemical industry limited.

White carbon black, 3000 mesh.

Example 1

A preparation method of a powdery non-silicon type foam inhibitor comprises the following steps:

S1, adding 25g of modified grease, 20g of polyether and 0.4g of 98wt% concentrated sulfuric acid into a high-speed stirrer with a heating jacket, and stirring at 2000rpm at 200 ℃ for 6 hours to obtain polyether modified grease;

S2, adding the polyether modified grease in the S1, 8g of white carbon black and 5g of ethylene bis stearamide into a high-speed stirrer with a heating jacket, stirring at 2000rpm at 100 ℃ for 2 hours, drying for 30 minutes, and crushing by a ball mill to obtain the powdery non-silicon foam inhibitor.

The preparation method of the modified grease comprises the following steps:

step one, adding 65g of (3E) -1-amino-3-pentene-2-ol, 100g of corn oil and 1.5g of 5wt% sodium hydroxide aqueous solution into a three-neck flask with a stirrer, a reflux condenser and a thermometer, stirring and refluxing for 5 hours at 60 ℃, then carrying out normal pressure distillation under 0.05MPa to recover excessive grafting agent, standing for 1 hour to remove an oil layer, and washing with water to remove an alkaline catalyst and corn oil to obtain a mixture;

Step two, adding 30g 5,5,6,6,7,7,8,8,8-nonafluoro-2-methylene octanoic acid and 0.5g of 98wt% concentrated sulfuric acid into the mixture obtained in the step one, mixing, heating to 50 ℃, dropwise adding 85mL of 30wt% hydrogen peroxide, and stirring for 4 hours to obtain an oil-water mixed solution;

And step three, filtering the oil-water mixed solution obtained in the step two to obtain an upper layer oil layer, washing with water at 60 ℃ for 2 times, neutralizing with 50mL of 5wt% sodium hydroxide aqueous solution, washing with water at 60 ℃ for 3 times to neutrality, and distilling under reduced pressure for 1h under 0.02MPa to remove solvent and low-boiling impurities, thereby obtaining the modified oil.

Example 2

Example 2 of the present application differs from example 1 in that (3E) -1-amino-3-penten-2-ol in example 1 is replaced with trimethylol propane.

Example 3

Example 3 of the present application differs from example 1 in that (3E) -1-amino-3-penten-2-ol in example 1 is replaced with triphenylmethanol.

Example 4

Example 4 of the present application differs from example 1 in that 5,5,6,6,7,7,8,8,8-nonafluoro-2-methyleneoctanoic acid in example 1 was replaced with m-methylbenzoic acid.

Example 5

Example 5 of the present application differs from example 1 in that 5,5,6,6,7,7,8,8,8-nonafluoro-2-methyleneoctanoic acid in example 1 is replaced with succinic acid.

Comparative example 1

This comparative example 1 differs from example 1 in that (3E) -1-amino-3-penten-2-ol in example 1 was replaced with methanol.

Comparative example 2

This comparative example 2 differs from example 1 in that 5,5,6,6,7,7,8,8,8-nonafluoro-2-methyleneoctanoic acid in example 1 was replaced with formic acid.

Test example 1

Centrifugal stability test: 0.4g of the samples to be tested in examples 1-5 and comparative example 1 are taken and added into 100mL of water, the mixture is stirred uniformly, the mixture is centrifuged for 5min at 3000r/min, and the centrifugal stability of the samples to be tested is observed, if no delamination exists, the centrifugal stability is proved to be good. The test results are shown in Table I.

Table one centrifugal stability test results

Test example 2

Defoaming performance test: 20mL of a 2% aqueous solution of sodium dodecylbenzenesulfonate was added to a 50mL standard cuvette, the stopper was plugged, the mixture was shaken vertically at 60 times/min for 1min, 5 drops of 5% of the suds suppressors prepared in examples 1-5 and comparative examples 1-2 were added dropwise, and the total foam extinction time was recorded. The shorter the time, the higher the defoaming force.

Foam inhibition performance test: and (3) the liquid in the colorimetric tube after the defoaming test is not added with the foam inhibitor, is vertically oscillated for 20s at the speed of 60 times/min, is kept stand for inspecting the foam elimination time, and records the defoaming times. The foam inhibition performance is good or bad due to the number of times of defoaming. The time for the first foam to disappear is called the defoaming time, after which no more defoaming agent is added, and the foam disappearance time is observed after the second shaking is continued. The same is repeated until the foam vanishing time becomes a prescribed value, and the number of repetitions at this time is called defoaming number. The defoaming times are more, and the foam inhibition performance is good. The test results are shown in Table II.

Table II foam inhibition test results

From the results of the test data in tables one and two, it can be seen that the suds suppressing effect and stability of the powdered non-silicone suds suppressors prepared in example 1 are best. By observing examples 1-3 and comparative example 1, the suds suppressors prepared in example 1 had higher high speed dispersion test values than examples 2-3 and comparative example 1, while example 1 had better stability than comparative example 1, with the difference that a different grafting agent was used. The possible reason is that the grafting agent functions to carry out the alcoholysis reaction of corn oil under the oxidizing agent and the catalyst and other action conditions through the alcoholic hydroxyl group functional group contained in itself, but the grafting agent in example 1 contains an amine functional group and a double bond in addition to the alcoholic hydroxyl group having a polyol participating in the reaction. The amino functional group can react with double bonds and hydroxyl contained in corn oil, and the amino has certain hydrophilicity, so that the dispersibility and stability of the foam inhibitor in water can be improved. Meanwhile, double bonds contained in the (3E) -1-amino-3-pentene-2-alcohol are easy to carry out addition reaction with alcohol hydroxyl, and hydroxyl with stronger polarity is introduced, so that the modified grease has better hydrophilicity and dispersibility, and meanwhile, the crosslinking density of the modified grease polymer is increased, and the stable network space structure is formed. The double bond and amine group of the grafting agent in example 1 improve the hydrophilicity and dispersibility of the modified grease, and may influence the spatial configuration of the suds suppressor molecule, so that a dense film is more easily formed on the surface of the liquid, thereby improving the suds suppressing effect.

By observing examples 1, examples 4-5 and comparative example 2, it can be seen that example 1 has higher high-speed dispersion test values than examples 4-5 and comparative example 2, and that example 1 has better centrifugal stability test results than comparative example 2, with the difference that a different modifier is used. The possible reason is that the modifier is oxidized to a peroxyacid by the oxidizing agent, which in turn reacts with the double bonds in the corn oil to yield an epoxidized corn oil. The modifier in example 1 contains fluorine atoms in addition to the carboxyl functional groups which can be oxidized into peroxyacid by the oxidizing agent, and the foam inhibition effect of the foam inhibitor prepared in example 1 is best because the foam inhibition effect can be achieved by rapid permeation, wetting and spreading and foam membrane disruption due to the hydrophobicity and low surface tension of the fluorine atoms. Thus, by comparative analysis of the different grafting agents and different modifiers in groups as above, it was found that the stability and defoaming and foam suppressing effects of the suds suppressor prepared in example 1 were best.

Claims

1. A method for preparing a powdery non-silicon type antifoaming agent, characterized in that it comprises the following steps, measured in parts by weight:

S1, stirring 20-35 parts of modified oil, 20-40 parts of polyether, and 0.1-1 parts of acid catalyst at 120-150° C. for 4-8 hours to obtain polyether-modified oil;

S2, further mixing the polyether modified oil in S1, 5-10 parts of white carbon black, and 1-7 parts of ethylene bisstearamide at 90-120°C, drying and crushing to obtain a powdery non-silicon type antifoaming agent;

The preparation method of the modified oil comprises the following steps:

Step 1, stirring the grafting agent, natural oil and alkaline catalyst at 40-65° C. for 2-6 hours, then performing atmospheric distillation to recover excess grafting agent, then standing for 1-2 hours to remove the oil layer, washing with water to remove the alkaline catalyst and natural oil, and obtaining a mixture;

Step 2: add a modifier and an acid catalyst to the mixture in step 1, heat to 40-65°C, dropwise add an oxidant, stir for 2-6 hours, and obtain an oil-water mixture;

Step 3: Filter the oil-water mixture in step 2 to obtain the upper oil layer, wash it with 50-60°C water 1-2 times, neutralize it with 2-5wt% sodium hydroxide aqueous solution, wash it with 50-60°C water 2-3 times until the pH is neutral, and then distill under reduced pressure to remove the solvent and low-boiling impurities to obtain modified oil.

2. The method for preparing a powdery non-silicon type antifoaming agent according to claim 1, characterized in that the method for preparing the modified oil comprises the following steps, measured in parts by weight:

Step 1, stirring 60-85 parts of a grafting agent, 80-120 parts of natural oils and fats, and 0.5-2 parts of a basic catalyst at 40-65° C. for 2-6 hours, then performing atmospheric distillation to recover excess grafting agent, then standing for 1-2 hours to remove the oil layer, and washing with water to remove the basic catalyst and natural oils and fats to obtain a mixture;

Step 2: Add 20-40 parts of a modifier and 0.1-1 parts of an acidic catalyst to the mixture in step 1, heat to 40-65° C., dropwise add an oxidant, and stir for 2-6 hours to obtain an oil-water mixture;

3. The method for preparing a powdery non-silicon antifoaming agent according to claim 1, wherein the modifier is any one of m-toluic acid, succinic acid, and 5,5,6,6,7,7,8,8,8-nonafluoro-2-methyleneoctanoic acid.

4. The method for preparing a powdery non-silicon type antifoaming agent according to claim 3, wherein the modifier is 5,5,6,6,7,7,8,8,8-nonafluoro-2-methyleneoctanoic acid.

5. The method for preparing a powdery non-silicon type antifoaming agent according to claim 1, wherein the grafting agent is any one of trimethylolpropane, triphenylmethanol, and (3E)-1-amino-3-penten-2-ol.

6. The method for preparing a powdery non-silicon type antifoaming agent according to claim 1, wherein the oxidant is hydrogen peroxide.

7. The method for preparing a powdery non-silicon type antifoaming agent according to claim 1, wherein the natural oil is corn oil.

8. The method for preparing a powdery non-silicon type antifoaming agent according to claim 1, wherein the acidic catalyst is concentrated sulfuric acid.

9. A powdery non-silicon type antifoaming agent, characterized in that it is prepared by the method described in any one of claims 1 to 8.