A stable plant-based polymer defoamer and a method for preparing the same

Abstract

The application provides a stable plant-based polymer defoaming agent and a preparation method thereof, takes plant oil and derivatives thereof as a carrier, and introduces a polymer, so that the product stability is improved while good defoaming and foam suppressing performances are ensured; the application does not use an organic solvent, is more in line with the green and environmental protection concept, and can reduce VOC emission; the defoaming agent prepared by the application enhances the compatibility of a system when applied to the paint industry, and can reduce the corrosion of paint.

Description

Technical Field

[0001] This invention relates to an antifoaming agent, specifically to a plant-based polymer antifoaming agent and its preparation method. Background Technology

[0002] Mineral oil-based defoamers are well-established and widely used in water-based coatings. They typically consist of mineral oil, hydrophobic particles, thickeners, and emulsifiers, exhibiting good dispersibility and compatibility in water-based coatings, as well as effective defoaming and foam suppression properties. However, mineral oils are composed of alkanes, cycloalkanes, and aromatic hydrocarbons, resulting in high VOC (volatile organic compound) content, which does not meet industry environmental protection requirements. To reduce VOC content, researchers both domestically and internationally have used vegetable oils to partially or completely replace mineral oil in the preparation of vegetable oil-based defoamers.

[0003] CN104479439B describes the introduction of vegetable oil and its derivatives, along with mineral oil, into a system of alkyl silicone oil and silica. By controlling the average carbon number of the alkyl silicone oil, it achieves good miscibility with mineral oil, and the ratio of mineral oil to vegetable oil and its derivatives is controlled between 1:6 and 4:7. This effectively solves the problems of pinholes, edge shrinkage, and depressions in the coating film, while also improving the defoaming and foam-suppressing performance and stability of the defoamer. However, it does not discuss the stability and defoaming and foam-suppressing performance of the system when vegetable oil and its derivatives are used as the carrier alone, and the VOC content of the product is still relatively high. CN101991975B uses mineral oil as a carrier and simultaneously adds fatty acid metal soaps and fatty acid amides to improve product stability and further enhance defoaming and foam suppression performance. Although the defoaming and foam suppression performance and stability of the product are improved, the product still uses mineral oil as a carrier, resulting in high VOC content and poor environmental performance. Summary of the Invention

[0004] The present invention provides a stable plant-based polymer defoamer that is more in line with the concept of green and environmentally friendly development, reduces VOC emissions, and improves storage stability by introducing polymers while having good defoaming and foam-suppressing performance.

[0005] The components of the plant-based polymer defoamer of this invention are: A. Carrier The carrier is selected from vegetable oils and their derivatives, specifically from one or more of castor oil, palm oil, corn oil, rapeseed oil, soybean oil, sunflower oil, peanut oil, turpentine oil, methylated vegetable oil, and biodiesel. The derivatives of the vegetable oils include epoxidized compounds and amidated compounds of vegetable oils. The carrier accounts for 20-62% of the total mass of the defoamer. B. Polymer The polymer is prepared from the following components, and the amount of the polymer accounts for 25-72% of the total mass of the defoamer: B1, Monomer 1 The monomer 1 is selected from alkyl acrylates or alkyl methacrylates; preferably isooctyl acrylate or isooctyl methacrylate. B2, Monomer 2 The monomer 2 is selected from hydroxyalkyl acrylate and hydroxyalkyl methacrylate; preferably hydroxyethyl acrylate and hydroxyethyl methacrylate. B3, Monomer 3 The monomer 3 is selected from acrylamide monomers; preferably acrylamide, N,N-dimethylacrylamide, or N,N-diethylacrylamide. The total amount of the three monomers used accounts for 25-65% of the total polymer mass; B4, Unsaturated end-capped polyether The general formula of the unsaturated end-capped polyether is as follows: CH2=CHCH2(C2H4O) m (C3H6O) n R 1 Where R 1 Alkyl, phenyl, or such as the general formula CH3(CH2) with 1 to 4 carbon atoms. x The CO- group is shown, where x is an integer from 8 to 16; the subscripts m and n are integers, and the ratio of m to n is 1:9 to 3:2; the molecular weight of the unsaturated end-capped polyether is between 400 and 2500; the amount of the unsaturated end-capped polyether accounts for 2 to 8% of the total polymer mass; B5, α-olefins The α-olefin is any one or a mixture of linear α-olefins, α-aromatic olefins, or branched α-olefins, including α-octene, α-decene, α-dodecene, α-tetradecene, α-hexadecene, α-octadecene, α-eicosene, C20-C24 linear α-olefin mixtures, C24-C28 linear α-olefin mixtures, α-triaconene, α-methylstyrene, and α-styrene. It can be used alone or in any proportion; the amount used is 2-6% of the total polymer mass. B6. Diluent The diluent is selected from vegetable oils and their derivatives, specifically from one or more of castor oil, palm oil, corn oil, rapeseed oil, soybean oil, sunflower oil, peanut oil, turpentine oil, methylated vegetable oil, and biodiesel. The vegetable oil derivatives include epoxidized compounds and amidated compounds of vegetable oils. The amount used accounts for 22-65% of the total polymer mass. B7. Initiator The initiator is selected from 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2,4-dimethylpentanonitrile), 2,2'-azobis(2-methylbutanonitrile), and benzoyl peroxide; specifically, it is selected from benzoyl peroxide; the amount used accounts for 0.2% to 1% of the total polymer mass; C. Silicon dioxide The silica has a specific surface area of ​​20~500m². 2 / g of precipitated hydrophobic silica, accounting for 2~8% of the total mass of the defoamer; the silica is used in two parts, C1 and C2. D. Thickener The thickener is selected from xanthan gum, guar gum, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, polyacrylic acid, polyacrylamide, and polyacrylate, and is more preferably polyacrylic acid, polyacrylamide, and polyacrylate; the amount used accounts for 3-10% of the total mass of the defoamer; The method for preparing a stable plant-based polymer defoamer according to the present invention is as follows: Step 1: Polymer Preparation 1) Add monomer 1, monomer 2, monomer 3, unsaturated end-capped polyether, α-olefin, and 1 / 2 initiator to a container and stir until homogeneous to form mixture M; 2) Add the diluent and the remaining 1 / 2 of the initiator to the container, stir evenly, and after the initiator is fully dissolved, raise the temperature to 60~100℃, and add the mixture M dropwise, controlling the dropwise addition time to 1~5h. During the dropwise addition, keep the temperature at 60~100℃ through circulating water. After the dropwise addition is completed, keep it at the temperature for 1~3h, and distill it for 0.5~3h under a vacuum of -0.09~-0.1MPa and a temperature of 90~110℃ to remove small molecule impurities and obtain the final polymer N. Step 2: Place the specified amount of carrier and silica C1 in a reaction vessel, raise the temperature to 40~240℃, and disperse at high speed of 500~1000 rpm for 0.5-2h to obtain mixture E; Step 3: Place the specified amount of polymer and silica C2 in a reaction vessel, raise the temperature to 40~140℃, disperse at high speed of 500~1000rpm for 0.5-2h to obtain mixture F; under the heat preservation state, add mixture E and thickener, mix and stir evenly, and cool to room temperature to obtain the plant-based polymer defoamer P.

[0006] The advantages of this invention are: (1) This invention does not use solvents, but uses vegetable oil and its derivatives instead of traditional mineral oil, which is more in line with current environmental protection requirements and reduces VOC emissions; when applied to the coating industry, it can reduce the corrosiveness of coatings. (2) The polymer of the present invention uses vegetable oil instead of traditional diluent in the preparation process, which reduces the residue of harmful substances and increases the compatibility of the system. (3) The present invention introduces three different polymer monomers at the same time to prepare the polymer. The acrylic monomer improves the compatibility of the defoamer, and the olefin monomer improves the compatibility of the polymer with the carrier oil, thereby further improving the stability of the defoamer. Detailed Implementation

[0007] In the following examples, unsaturated end-capped polyether B4 is used: Example 1: Step 1: Polymer Preparation 1) Add 26g of isooctyl acrylate, hydroxyethyl acrylate, N,N-dimethylacrylamide mixture, 2.6g of B4-2, 6g of α-octadecene, and 0.2g of 2,2'-azobis(2-methylbutyronitrile) to a container and stir until homogeneous to form mixture M1; 2) Add 65g of soybean oil and the remaining 0.2g of 2,2'-azobis(2-methylbutyronitrile) to a container, stir well to fully dissolve the initiator, raise the temperature to 65℃, and add the mixture M1 dropwise over a period of 4 hours. During the dropwise addition, maintain the temperature at 65℃ using circulating water. After the dropwise addition is complete, keep the temperature at 1.5 hours, and then distill for 3 hours under a vacuum of -0.09MPa and a temperature of 90℃ to remove small molecule impurities, thus obtaining the final polymer N1. Step 2: Add 30g of soybean oil and 2g of [unclear - possibly a specific surface area]... 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 40℃, and it was dispersed at high speed of 1000rpm for 1h to obtain mixture E1; Step 3: Combine 60g of polymer N1 and 2g of polymer with a specific surface area of ​​200m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 40℃, and the mixture was dispersed at 1000rpm for 0.5h to obtain mixture F1; under the condition of heat preservation, mixture E1 and 6g of polyacrylic acid were added and stirred evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P1.

[0008] Example 2: Step 1: Polymer Preparation 1) Add 25g of isooctyl methacrylate, hydroxyethyl methacrylate, acrylamide mixture, 7g of B4-1, 5g of α-dodecene and α-tetradecene, and 0.5g of benzoyl peroxide to a container and stir until homogeneous to form mixture M2; 2) Add 62g of rapeseed oil and the remaining 0.5g of benzoyl peroxide to a container, stir well to fully dissolve the initiator, raise the temperature to 80℃, and add the mixture M2 dropwise over a period of 3 hours. During the dropwise addition, maintain the temperature at 80℃ using circulating water. After the dropwise addition is complete, keep the temperature at 1 hour, and then distill for 2.5 hours under a vacuum of -0.09MPa and a temperature of 98℃ to remove small molecule impurities and obtain polymer N2. Step 2: Add 20g of rapeseed oil and 1.5g of a substance with a specific surface area of ​​300m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 240℃, and the mixture was dispersed at 500rpm for 0.5h to obtain mixture E2. Step 3: Add 72g of polymer N2 and 0.5g of a polymer with a specific surface area of ​​300m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 140℃, and the mixture was dispersed at 500rpm for 0.5h to obtain mixture F2; under the condition of heat preservation, mixture E2 and 6g of polyacrylamide were added and mixed evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P2.

[0009] Example 3: Step 1: Polymer Preparation 1) Add 39.5g of isooctyl acrylate, hydroxyethyl methacrylate, N,N-diethylacrylamide mixture, 8g of B4-4, 5g of α-eicosene and α-trianene, and 0.25g of 2,2'-azobis(2-methylbutyronitrile) to a container and stir until homogeneous to form mixture M3; 2) Add 47g of peanut oil and the remaining 0.25g of 2,2'-azobis(2-methylbutyronitrile) to a container, stir well, and after the initiator is fully dissolved, raise the temperature to 85℃, and add the mixture M3 dropwise, controlling the dropwise addition time to 3h. During the dropwise addition, keep the temperature at 85℃ through circulating water. After the dropwise addition is completed, keep it at the temperature for 1h, and distill it for 2.8h under a vacuum of -0.1MPa and a temperature of 92℃ to remove small molecule impurities and obtain polymer N3. Step 2: Add 50g of peanut oil and 1g of [unclear - possibly a specific surface area]... 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 100℃, and it was dispersed at high speed of 600rpm for 1.5h to obtain mixture E3; Step 3: Add 41g of polymer N3 and 4g of a specific surface area of ​​400m² 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 80℃, and the mixture was dispersed at 800rpm for 1h to obtain mixture F3; under the condition of heat preservation, mixture E3 and 4g of polyacrylate were added and mixed evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P3.

[0010] Example 4: Step 1: Polymer Preparation 1) Add 46g of isooctyl methacrylate, hydroxyethyl acrylate, N,N-diethylacrylamide mixture, 5g of B4-4, 5g of α-decene and α-hexadecene, and 0.3g of benzoyl peroxide to a container and stir until homogeneous to form mixture M4; 2) Add 43.4g of castor oil and the remaining 0.3g of benzoyl peroxide to a container, stir well to fully dissolve the initiator, raise the temperature to 90℃, and add the mixture M4 dropwise over a period of 5 hours. During the dropwise addition, maintain the temperature at 90℃ using circulating water. After the dropwise addition is complete, keep the temperature at 90℃ for 2 hours, and then distill for 1.5 hours under a vacuum of -0.1MPa and a temperature of 94℃ to remove small molecule impurities and obtain polymer N4. Step 2: Add 37g of castor oil and 3g of a specific surface area of ​​450m² 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 150℃, and the mixture was dispersed at high speed of 900rpm for 2h to obtain mixture E4. Step 3: Combine 48g of polymer N4 and 2g of a polymer with a specific surface area of ​​450m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 120℃, and the mixture was dispersed at 700rpm for 1.5h to obtain mixture F4; under the condition of heat preservation, mixture E4 and 10g of polyacrylic acid were added and stirred evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P4.

[0011] Example 5: Step 1: Polymer Preparation 1) Add 47g of methyl acrylate, hydroxybutyl acrylate, N-hydroxymethylacrylamide mixture, 3g of B4-3, 4g of α-octene, and 0.1g of benzoyl peroxide to a container and stir until homogeneous to form mixture M5; 2) Add 45.8g of epoxidized peanut oil and the remaining 0.1g of benzoyl peroxide to a container, stir evenly to fully dissolve the initiator, raise the temperature to 100℃, and add the mixture M5 dropwise, controlling the dropwise addition time to 1.5h. During the dropwise addition, maintain the temperature at 100℃ through circulating water. After the dropwise addition is completed, keep warm for 3h, and distill at a vacuum of -0.09MPa and a temperature of 100℃ for 0.5h to remove small molecule impurities and obtain polymer N5. Step 2: Combine 62g of epoxidized peanut oil and 1.5g of [unclear - possibly a specific surface area]... 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 220℃, and the mixture was dispersed at 550rpm for 1h to obtain mixture E5. Step 3: Add 30g of polymer N5 and 3.5g of a specific surface area of ​​500m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 60℃, and the mixture was dispersed at 600rpm for 2h to obtain mixture F5; under the heat preservation condition, mixture E5 and 3g of xanthan gum were added and mixed evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P5.

[0012] Example 6: Step 1: Polymer Preparation 1) Add 47g of methyl methacrylate, hydroxypropyl acrylate, N-hydroxymethylmethacrylamide mixture, 2g of B4-3, 3g of α-triaconene and α-methylstyrene, α-styrene, and 0.4g of 2,2'-azobis(2-methylpropionitrile) to a container and stir until homogeneous to form mixture M6; 2) Add 47.2g of corn oil and the remaining 0.4g of 2,2'-azobis(2-methylpropionitrile) to a container, stir well to fully dissolve the initiator, raise the temperature to 85℃, and add the mixture M6 dropwise over a period of 1 hour. During the dropwise addition, maintain the temperature at 85℃ using circulating water. After the dropwise addition is complete, keep the temperature at 2 hours, and then distill at a vacuum of -0.1MPa and a temperature of 92℃ for 2 hours to remove small molecule impurities, thus obtaining polymer N6. Step 2: Add 59g of corn oil and 5g of a specific surface area of ​​100m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 100℃, and the mixture was dispersed at high speed of 900rpm for 1.5h to obtain mixture E6. Step 3: Combine 25g of polymer N6 and 1g of polymer with a specific surface area of ​​100m² 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 80℃, and the mixture was dispersed at 700rpm for 1h to obtain mixture F6; under the condition of heat preservation, mixture E6 and 10g of hydroxyethyl cellulose were added and stirred evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P6.

[0013] Example 7: Step 1: Polymer Preparation 1) Add 39g of butyl acrylate, hydroxybutyl acrylate, N-hydroxymethylmethacrylamide mixture, 6g of B4-1, 5g of α-dodecene and α-trianene, and 0.5g of 2,2'-azobis(2-methylpropionitrile) to a container and stir until homogeneous to form mixture M7; 2) Add 49g of epoxy castor oil and the remaining 0.5g of 2,2'-azobis(2-methylpropionitrile) to a container, stir until the initiator is fully dissolved, raise the temperature to 60℃, and add the mixture M7 dropwise over a period of 5 hours. During the dropwise addition, maintain the temperature at 60℃ using circulating water. After the dropwise addition is complete, keep the mixture at this temperature for 2 hours, and then distill it for 2 hours under a vacuum of -0.1MPa and a temperature of 90℃ to remove small molecule impurities, thus obtaining polymer N7. Step 2: Add 40g of epoxy castor oil and 2g of a specific surface area of ​​80m² 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 180℃, and the mixture was dispersed at high speed of 600rpm for 2h to obtain mixture E7. Step 3: Combine 45g of polymer N7 and 5g of a polymer with a specific surface area of ​​80m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 130℃, and the mixture was dispersed at 800rpm for 0.5h to obtain mixture F7; under the condition of heat preservation, mixture E7 and 8g of guar gum were added and mixed evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P7.

[0014] Example 8: Step 1: Polymer Preparation 1) Add 65g of octadecyl acrylate, hydroxypropyl acrylate, acrylamide mixture, 5g of B4-2, 4g of α-styrene, and 0.1g of benzoyl peroxide to a container and stir until homogeneous to form mixture M8; 2) Add 25.8g of turpentine oil, amidated soybean oil, and the remaining 0.1g of benzoyl peroxide to a container, stir well, and after the initiator is fully dissolved, raise the temperature to 70℃, and add the mixture M8 dropwise, controlling the dropwise addition time to 4.5h. During the dropwise addition, maintain the temperature at 70℃ through circulating water. After the dropwise addition is completed, keep warm for 2h, and distill for 1.8h under a vacuum of -0.09MPa and a temperature of 90℃ to remove small molecule impurities, and obtain polymer N8. Step 2: Mix 41g of turpentine oil with amidated soybean oil and 4g of oil with a specific surface area of ​​20m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 150℃, and the mixture was dispersed at 850rpm for 2h to obtain mixture E8. Step 3: Combine 42g of polymer N8 and 4g of material with a specific surface area of ​​20m² 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 50℃, and the mixture was dispersed at 650rpm for 1h to obtain mixture F8; under the heat preservation condition, mixture E8 and 9g of carboxymethyl cellulose were added and stirred evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P8.

[0015] Example 9: Step 1: Polymer Preparation 1) Add 64.2g of dodecyl methacrylate, hydroxyethyl acrylate, N,N-dimethylacrylamide mixture, 7g of B4-4, 6g of α-methylstyrene and α-tetradecene, and 0.5g of benzoyl peroxide to a container and stir until homogeneous to form mixture M9; 2) Add 22g of biodiesel, epoxidized peanut oil, and the remaining 0.3g of benzoyl peroxide to a container, stir well, and after the initiator is fully dissolved, raise the temperature to 75℃, and add the mixture M9 dropwise, controlling the dropwise addition time to 2.5h. During the dropwise addition, maintain the temperature at 75℃ through circulating water. After the dropwise addition is completed, keep it at the temperature for 2h, and then distill it for 1.5h under a vacuum of -0.1MPa and a temperature of 95℃ to remove small molecule impurities, and obtain polymer N9. Step 2: Mix 20g of biodiesel with epoxidized peanut oil and 1g of oil with a specific surface area of ​​260m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 120℃, and the mixture was dispersed at 750rpm for 1.5h to obtain mixture E9. Step 3: Combine 72g of polymer N9 and 1g of polymer with a specific surface area of ​​260m² 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 70℃, and the mixture was dispersed at 800rpm for 1.5h to obtain mixture F9; under the condition of heat preservation, mixture E9 and 6g of methylcellulose were added and stirred evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P9.

[0016] Example 10: Step 1: Polymer Preparation 1) Add 45g of ethyl acrylate, hydroxybutyl acrylate, N,N-diethylacrylamide mixture, 2g of B4-1, 2g of α-octadecene and α-eicosene, and 0.5g of 2,2'-azobis(2,4-dimethylpentanonitrile) to a container and stir until homogeneous to form mixture M; 2) Add 50g of castor oil, epoxidized castor oil, and the remaining 0.5g of 2,2'-azobis(2,4-dimethylpentanonitrile) to a container, stir until the initiator is fully dissolved, raise the temperature to 90℃, and add the mixture M10 dropwise over a period of 1 hour. During the dropwise addition, maintain the temperature at 90℃ using circulating water. After the dropwise addition is complete, keep the temperature at 3 hours, and then distill at a vacuum of -0.1MPa and a temperature of 100℃ for 1 hour to remove small molecule impurities, thus obtaining polymer N10. Step 2: Mix 58g of castor oil with epoxidized castor oil and 5g of castor oil with a specific surface area of ​​250m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 200℃, and the mixture was dispersed at high speed of 500rpm for 2h to obtain mixture E10. Step 3: Combine 25g of polymer N10 and 2g of a polymer with a specific surface area of ​​250m² 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 100℃, and the mixture was dispersed at 900rpm for 1h to obtain mixture F10; under the condition of heat preservation, mixture E10 and 10g of methylcellulose were added and stirred evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer.

[0017] Comparative Example 1 Step 1: Polymer Preparation 1) Add 26g of hydroxyethyl acrylate, N,N-dimethylacrylamide mixture, 2.6g of B4-2, 6g of α-octadecene, and 0.2g of 2,2'-azobis(2-methylbutyronitrile) to a container and stir until homogeneous to form mixture M11; 2) Add 65g of soybean oil and the remaining 0.2g of 2,2'-azobis(2-methylbutyronitrile) to a container, stir well, and after the initiator is fully dissolved, raise the temperature to 65℃, and add the mixture M11 dropwise, controlling the dropwise addition time to 4h. During the dropwise addition, keep the temperature at 65℃ through circulating water. After the dropwise addition is completed, keep it at the temperature for 1.5h, and distill it for 3h under a vacuum of -0.09MPa and a temperature of 90℃ to remove small molecule impurities, and obtain the final polymer N11. Step 2: Add 30g of soybean oil and 2g of [unclear - possibly a specific surface area]... 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 40℃, and it was dispersed at high speed of 1000rpm for 1h to obtain mixture E1; Step 3: Combine 60g of polymer N11 and 2g of polymer with a specific surface area of ​​200m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 40℃, and the mixture was dispersed at 1000rpm for 0.5h to obtain mixture F11; under the condition of heat preservation, mixture E1 and 6g of polyacrylic acid were added and stirred evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P11.

[0018] Comparative Example 2 Step 1: Polymer Preparation 1) Add 25g of isooctyl methacrylate, acrylamide mixture, 7g of B4-1, 5g of α-dodecene and α-tetradecene, and 0.5g of benzoyl peroxide to a container and stir until homogeneous to form mixture M12; 2) Add 62g of rapeseed oil and the remaining 0.5g of benzoyl peroxide to a container, stir well to fully dissolve the initiator, raise the temperature to 80℃, and add the mixture M2 dropwise over a period of 3 hours. During the dropwise addition, maintain the temperature at 80℃ using circulating water. After the dropwise addition is complete, keep the temperature at 1 hour, and then distill for 2.5 hours under a vacuum of -0.09MPa and a temperature of 98℃ to remove small molecule impurities and obtain polymer N12. Step 2: Add 20g of rapeseed oil and 1.5g of a substance with a specific surface area of ​​300m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 240℃, and the mixture was dispersed at 500rpm for 0.5h to obtain mixture E2. Step 3: Add 72g of polymer N12 and 0.5g of a polymer with a specific surface area of ​​300m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 140℃, and the mixture was dispersed at 500rpm for 0.5h to obtain mixture F12; under the condition of heat preservation, mixture E2 and 6g of polyacrylamide were added and mixed evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P12.

[0019] Comparative Example 3 Step 1: Polymer Preparation 1) Add 39.5g of isooctyl acrylate, hydroxyethyl methacrylate mixture, 8g of B4-4, 5g of α-eicosene and α-trianene, and 0.25g of 2,2'-azobis(2-methylbutyronitrile) to a container and stir until homogeneous to form mixture M13; 2) Add 47g of peanut oil and the remaining 0.25g of 2,2'-azobis(2-methylbutyronitrile) to a container, stir well to fully dissolve the initiator, raise the temperature to 85℃, and add the mixture M3 dropwise over a period of 3 hours. During the dropwise addition, maintain the temperature at 85℃ using circulating water. After the dropwise addition is complete, keep the temperature at 1 hour, and then distill for 2.8 hours under a vacuum of -0.1MPa and a temperature of 92℃ to remove small molecule impurities, thus obtaining polymer N13. Step 2: Add 50g of peanut oil and 1g of [unclear - possibly a specific surface area]... 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 100℃, and it was dispersed at high speed of 600rpm for 1.5h to obtain mixture E3; Step 3: Combine 41g of polymer N13 and 4g of material with a specific surface area of ​​400m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 80℃, and the mixture was dispersed at 800rpm for 1h to obtain mixture F13; under the condition of heat preservation, mixture E3 and 4g of polyacrylate were added and mixed and stirred evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P13.

[0020] Comparative Example 4 Step 1: Polymer Preparation 1) Add 46g of isooctyl methacrylate, hydroxyethyl acrylate, N,N-diethylacrylamide mixture, 5g of B4-4, 5g of α-decene and α-hexadecene, and 0.3g of benzoyl peroxide to a container and stir until homogeneous to form mixture M4; 2) Add 43.4g of polyethylene glycol (molecular weight 800) and the remaining 0.3g of benzoyl peroxide to a container, stir until the initiator is fully dissolved, raise the temperature to 90℃, and add the mixture M4 dropwise over a period of 5 hours. During the dropwise addition, maintain the temperature at 90℃ using circulating water. After the dropwise addition is complete, keep the mixture at this temperature for 2 hours, and then distill it for 1.5 hours under a vacuum of -0.1MPa and a temperature of 94℃ to remove small molecule impurities, thus obtaining polymer N14. Step 2: Add 37g of castor oil and 3g of a specific surface area of ​​450m² 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 150℃, and the mixture was dispersed at high speed of 900rpm for 2h to obtain mixture E4. Step 3: Combine 48g of polymer N14 and 2g of a polymer with a specific surface area of ​​450m² 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 120℃, and the mixture was dispersed at 700rpm for 1.5h to obtain mixture F14; under the condition of heat preservation, mixture E4 and 10g of polyacrylic acid were added and mixed evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P14.

[0021] Comparative Example 5 Step 1: Preparation of organosilicon polymer: Organosilicon polymer N15 was prepared according to Example 1 in patent ZL201410794639.1; Step 2: Combine 62g of epoxidized peanut oil and 1.5g of [unclear - possibly a specific surface area]... 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 220℃, and the mixture was dispersed at 550rpm for 1h to obtain mixture E5. Step 3: Combine 30g of polymer N15 and 3.5g of a polymer with a specific surface area of ​​500m². 2 / g of precipitated hydrophobic silica was placed in a reaction vessel, the temperature was raised to 60℃, and the mixture was dispersed at 600rpm for 2h to obtain mixture F15; under the heat preservation condition, mixture E5 and 3g of xanthan gum were added and mixed evenly, and then cooled to room temperature to obtain the plant-based polymer defoamer P15.

[0022] Comparative Example 6 Step 1: Polymer Preparation 1) Add 47g of methyl methacrylate, hydroxypropyl acrylate, N-hydroxymethylmethacrylamide mixture, 2g of B4-3, 3g of α-triaconene and α-methylstyrene, α-styrene, and 0.4g of 2,2'-azobis(2-methylpropionitrile) to a container and stir until homogeneous to form mixture M6; 2) Add 47.2g of corn oil and the remaining 0.4g of 2,2'-azobis(2-methylpropionitrile) to a container, stir well to fully dissolve the initiator, raise the temperature to 85℃, and add the mixture M6 dropwise over a period of 1 hour. During the dropwise addition, maintain the temperature at 85℃ using circulating water. After the dropwise addition is complete, keep the temperature at 2 hours, and then distill at a vacuum of -0.1MPa and a temperature of 92℃ for 2 hours to remove small molecule impurities, thus obtaining polymer N6. Step 2: Add 59g of corn oil and 6g of a specific surface area of ​​100m² 2 / g of precipitated hydrophobic silica and 25g of polymer N6 were placed in a reaction vessel, the temperature was raised to 100℃, and the mixture was dispersed at 900rpm for 1.5h to obtain mixture E6. Under the condition of heat preservation, 10g of hydroxyethyl cellulose was added and mixed evenly. The mixture was then cooled to room temperature to obtain the plant-based polymer defoamer P16.

[0023] Performance testing (1) Defoaming and foam suppression performance test Test method: Add 135g of prepared coating to a 500ml stainless steel cup, then add 15g of styrene-acrylic emulsion. Use a high-speed disperser to stir at 600rpm for 1min to ensure uniform mixing of the coating and styrene-acrylic emulsion. Then add 1% thickener and 0.2% 2-amino-2-methyl-1-propanol, and continue stirring at 600rpm for 1min. Finally, add 0.3% defoamer and stir at 600rpm for 6min. Immediately after stopping stirring, pour the mixture into a 100ml graduated cylinder and record the mass m and volume V. Calculate the specific gravity = m / V. The larger the value, the better the performance of the defoamer.

[0024] (2) Compatibility test Test method: After the above high-speed dispersed coating is left to stand for 10 minutes, a small amount is taken out and placed on a glass plate. The coating is then uniformly scraped and leveled using a 75µm wet film preparation device. The state of the coating is observed and indicated by a grade. The higher the grade, the better the compatibility.

[0025] Results of foam suppression and compatibility tests: (2) Stability test The stability of the samples was tested using a Formulaction / Turbiscan Tower / Multiple Light Scattering Stability Analyzer at a temperature of 40℃ and a sample volume of 20g. The lower the TSI index in the test results, the better the sample stability.

[0026] Stability test results:

Claims

1. A stable plant-based polymer defoamer, wherein the components of the defoamer include: A. Carrier The carrier is selected from vegetable oils and their derivatives, specifically castor oil, palm oil, corn oil, rapeseed oil, soybean oil, sunflower oil, peanut oil, and turpentine oil. The derivatives of the vegetable oils include epoxidized compounds of vegetable oils, amidated compounds of vegetable oils, methylated vegetable oils, and biodiesel. Specifically, one or more of the vegetable oils and their derivatives are selected. B. Polymer The polymer is prepared from the following components, and the amount of the polymer accounts for 25-72% of the total mass of the defoamer: B1, Monomer 1 The monomer 1 is selected from alkyl acrylates or alkyl methacrylates; B2, Monomer 2 The monomer 2 is selected from hydroxyalkyl acrylate and hydroxyalkyl methacrylate; specifically, it is selected from one or more of hydroxyethyl acrylate and hydroxyethyl methacrylate. B3, Monomer 3 The monomer 3 is selected from acrylamide monomers; specifically, it is selected from one or more of acrylamide, N,N-dimethylacrylamide, and N,N-diethylacrylamide. The total amount of the three monomers used accounts for 25-65% of the total polymer mass; B4, Unsaturated end-capped polyether The general formula of the unsaturated end-capped polyether is as follows: CH2=CHCH2(C2H4O) m (C3H6O) n R 1 Where R 1 Alkyl, phenyl, or such as the general formula CH3(CH2) with 1 to 4 carbon atoms. x The CO- group is shown, where x is an integer from 8 to 16; the subscripts m and n are integers, and the ratio of m to n is 1:9 to 3:2; the molecular weight of the unsaturated end-capped polyether is between 400 and 2500; the amount of the unsaturated end-capped polyether accounts for 2 to 8% of the total polymer mass; B5, α-olefins The α-olefin is any one or a mixture of linear α-olefins, α-aromatic olefins, or branched α-olefins, including α-octene, α-decene, α-dodecene, α-tetradecene, α-hexadecene, α-octadecene, α-eicosene, C20-C24 linear α-olefin mixtures, C24-C28 linear α-olefin mixtures, α-triaconene, α-methylstyrene, and α-styrene; the amount used accounts for 2-6% of the total polymer mass. B6. Diluent The diluent is selected from vegetable oils and their derivatives, specifically castor oil, palm oil, corn oil, rapeseed oil, soybean oil, sunflower oil, peanut oil, and turpentine oil. The derivatives of the vegetable oils include epoxidized compounds of vegetable oils, amidated compounds of vegetable oils, methylated vegetable oils, and biodiesel, specifically selected from one or more of the vegetable oils and their derivatives, and the amount used accounts for 22-65% of the total mass of the polymer. B7. Initiator The initiator is selected from one of 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2,4-dimethylpentanonitrile), 2,2'-azobis(2-methylbutanonitrile), and benzoyl peroxide; the amount used accounts for 0.2% to 1% of the total polymer mass; C. Silicon dioxide The silica has a specific surface area of ​​20~500m². 2 / g of precipitated hydrophobic silica; the silica is used in two parts, C1 and C2; D. Thickener The thickener is selected from one or more of xanthan gum, guar gum, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, polyacrylic acid, polyacrylamide, and polyacrylate. The preparation method of the stable plant-based polymer defoamer is as follows: Step 1: Polymer Preparation 1) Add monomer 1, monomer 2, monomer 3, unsaturated end-capped polyether, α-olefin, and 1 / 2 initiator to a container and stir until homogeneous to form mixture M; 2) Add the diluent and the remaining 1 / 2 of the initiator to the container, stir evenly, and after the initiator is fully dissolved, raise the temperature to 60~100℃, and add the mixture M dropwise, controlling the dropwise addition time to 1~5h. During the dropwise addition, keep the temperature at 60~100℃ through circulating water. After the dropwise addition is completed, keep it at the temperature for 1~3h, and distill it for 0.5~3h under a vacuum of -0.09~-0.1MPa and a temperature of 90~110℃ to remove small molecule impurities and obtain the final polymer N. Step 2: Place the specified amount of carrier and silica C1 in a reaction vessel, raise the temperature to 40~240℃, and disperse at high speed of 500~1000 rpm for 0.5-2h to obtain mixture E; Step 3: Place the specified amount of polymer and silica C2 in a reaction vessel, raise the temperature to 40~140℃, disperse at high speed of 500~1000rpm for 0.5-2h to obtain mixture F; under the heat preservation state, add mixture E and thickener, mix and stir evenly, and cool to room temperature to obtain the plant-based polymer defoamer P.

2. The stable plant-based polymer defoamer according to claim 1, characterized in that, The carrier is used in an amount that accounts for 20-62% of the total mass of the defoamer.

3. The stable plant-based polymer defoamer according to claim 1, characterized in that, The amount of silica used accounts for 2-8% of the total mass of the defoamer.

4. The stable plant-based polymer defoamer according to claim 1, characterized in that, The amount of thickener used accounts for 3 to 10% of the total mass of the defoamer.

5. The stable plant-based polymer defoamer according to claim 1, characterized in that, The monomer 1 is selected from isooctyl acrylate and isooctyl methacrylate.

6. The stable plant-based polymer defoamer according to claim 1, characterized in that, The initiator is selected from benzoyl peroxide.

7. The stable plant-based polymer defoamer according to claim 1, wherein the thickener is selected from polyacrylic acid, polyacrylamide, and polyacrylate.

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