Preparation method of oil-proofing agent based on polymerization of acrylic acid and organic silicon

Abstract

The invention relates to a preparation method of an oil-proofing agent based on polymerization of acrylic acid and organic silicon, and belongs to the technical field of polymer synthesis. The preparation method comprises the following steps: adding methyl acrylate, hydroxyethyl acrylate, dithiothreitol, m-trifluoromethylcinnamyl aldehyde and triethylamine into a reaction kettle, and stirring and heating to react; adding an initiator, and continuously reacting, so that the acrylic monomer is subjected to polymerization reaction to form a polymer with good stability and mobility; alpha, omega-dihydroxy polydimethylsiloxane is continuously added, the reaction is continued, and the organosilicon linear body and the polymer are subjected to a polymerization reaction; adding an emulsifier, stirring, mixing and reacting to obtain an oil-proofing agent; the oil-proof agent is added into the lunch box paper pulp and is uniformly stirred, so that the polymer is uniformly distributed on the surface of the lunch box paper pulp to form a compact oil-proof film, and the attachment of oil stains is effectively prevented; the oil-proof agent prepared by the invention has good oil-proof performance, can effectively prevent oil stain adhesion, and keeps food packages and tableware clean.

Description

Technical Field

[0001] The invention relates to the technical field of polymer synthesis, in particular to a method for preparing an oil-proofing agent based on polymerization of acrylic acid and organosilicon. Background Art

[0002] In modern life, the cleanliness of food packaging and tableware is a focus of people's attention. Food packaging and tableware are often attached with oil stains, which not only affect the appearance, but also may cause hygiene and safety problems. Therefore, the application of oil repellents has become more and more widespread. Oil repellents are a chemical substance that can reduce surface tension and thus prevent oil stains from adhering.

[0003] Chinese patent CN116623461A: provides a fluorine-free oil-proof agent for pulp food containers and tableware and its production process, wherein an adhesive and 2-ethylhexyl acrylate are added to deionized water, and stirred at a low speed of 60-70 rpm to obtain a mixed solution A, wherein the adhesive is one or more of hydroxypropyl methylcellulose, polyvinyl pyrrolidone, polyacrylamide, and chitosan; modified starch is added to deionized water, and stirred at a low speed at a temperature of 70-80°C to obtain a modified starch solution; emulsified paraffin and a filler are added to the modified starch solution, wherein the filler is one or more of calcium carbonate, quartz powder, titanium dioxide, montmorillonite, and glass powder, and ultrasonic vibration is performed to disperse the mixture evenly to obtain a mixed solution B; when in use, the mixed solution A is first stirred evenly with the pulp, and then the mixed solution B is added and continued to be stirred evenly, and the mixed solution A and the mixed solution B are used as the fluorine-free oil-proof agent.

[0004] Chinese patent CN117626705A: provides a fluorine-free oil-proof agent and its preparation method and application, wherein the fluorine-free oil-proof agent comprises the following raw materials in parts by weight: 2-5 parts of polyvinyl alcohol, 15-25 parts of barrier kaolin, 2-5 parts of oxidized polyethylene wax, 5-15 parts of octadecyl methacrylate, and 58-60 parts of deionized water.

[0005] Chinese patent CN118930761A: Provides a fluorine-containing oil-proofing agent and a preparation method, comprising the following raw materials in parts by weight: fluorine-containing monomer: 60-70 parts by weight; acrylate monomer: 10-15 parts by weight; composite cross-linking monomer: 3-6 parts by weight; solvent: 100-150 parts by weight; initiator: 0.3-0.5 parts by weight; molecular weight regulator: 0.01-0.03 parts by weight; neutralizer: content 1-3% (based on the weight of the emulsion); antifreeze: 3-5 parts by weight; hydrophilic monomer: 5-15 parts by weight; retention aid: 4-6 parts by weight; antibacterial monomer 5-10 parts by weight; coating material monomer: 15-25 parts by weight.

[0006] The oil repellents prepared by the above patents and prior art are mainly divided into two categories: inorganic oil repellents and organic oil repellents. Inorganic oil repellents mainly use nanomaterials, such as nano silicon dioxide, nano aluminum oxide, etc., to achieve the effect of oil repellent. Organic oil repellents are mainly prepared by some polymer materials, such as polytetrafluoroethylene, polyvinylidene fluoride, etc. In addition, there are some oil repellents prepared by combining inorganic and organic materials.

[0007] Although existing oil-proofing agents can solve the oil-proofing problem of food packaging and tableware to a certain extent, there are still some problems. First, inorganic oil-proofing agents have migration and stability problems. After long-term use, they may migrate from the surface of the material, causing food contamination. Secondly, the preparation process of inorganic oil-proofing agents is complicated and the cost is high. Although organic oil-proofing agents have better stability, some harmful chemicals, such as Freon, may be used in the preparation process, which poses a certain threat to the environment and human health. Summary of the invention

[0008] In order to solve the above problems, the present invention provides a method for preparing an oil-proof agent based on polymerization of acrylic acid and silicone, and the operating steps are as follows: S1: According to weight parts, 12-18 parts of methyl acrylate, 10-16 parts of hydroxyethyl acrylate, 3-6 parts of dithiothreitol CAS No. 27565-41-9, 0.2-0.5 parts of m-trifluoromethylcinnamaldehyde CAS No. 871543-59-8, and 2-4 parts of triethylamine are added to a reaction kettle, and the mixture is stirred and heated to react; S2: Add 0.05-0.2 parts of initiator and continue the reaction for 90-120 minutes to polymerize the acrylic acid monomer to form a polymer; S3: Continue to add 28-36 parts of α,ω-dihydroxy polydimethylsiloxane and continue the reaction to make the silicone linear body and the polymer undergo polymerization reaction; S4: Add 60-80 parts of emulsifier, stir and mix to react, and obtain an oil-proofing agent.

[0009] The reaction temperature of S1 is 60-70°C, and the reaction time is 90-120min.

[0010] The initiator is one of azobisisobutyronitrile, dimethyl azobisisobutyrate, azoisobutylcyanoformamide and azobisisobutylamidine.

[0011] The reaction temperature of S3 is 70-80°C, and the reaction time is 150-180min.

[0012] The emulsifier is one of alkyl benzene ether polyoxyethylene ether, fatty alcohol polyoxyethylene ether, PEG-7 coconut oil glyceride, sodium stearate and sodium lauryl sulfate.

[0013] The reaction temperature of S4 is 50-60°C, and the reaction time is 40-60min.

[0014] The present invention also provides the above oil-proofing agent prepared based on the polymerization of acrylic acid and organic silicon.

[0015] The present invention also provides the use of the oil-proofing agent in the preparation of pulp, wherein the addition amount of the oil-proofing agent is 0.5-1% by mass of the pulp.

[0016] Reaction mechanism The reaction mechanism between the propenyl group of methyl acrylate and hydroxyethyl acrylate and the thiol group of dithiothreitol is mainly through the thiol-propenyl addition reaction. Specifically, the thiol group (-SH) can attack the propenyl group (-CH=CH2) under appropriate conditions to form a new carbon-sulfur bond.

[0017] The olefin of m-trifluoromethylcinnamaldehyde and the thiol of dithiothreitol also follow a similar thiol-propenyl addition reaction mechanism. In this reaction, the olefin double bond of m-trifluoromethylcinnamaldehyde acts as a nucleophile to react with the thiol of dithiothreitol to form a new carbon-sulfur bond.

[0018] Next, these monomer and polymer segments can be further linked together to form polymers with good stability and mobility through click chemistry polymerization, a highly efficient chemical reaction that can quickly and accurately connect two molecular fragments under mild conditions with minimal byproducts.

[0019] Finally, the silicone linear body polymerizes with the polymer to further improve the polymer's oil resistance. Silicone has good hydrophobicity and oleophobicity, so introducing it into the polymer can significantly improve the polymer's resistance to oil substances.

[0020] Technical Effects The mechanism by which compounds such as m-trifluoromethylcinnamaldehyde and dithiothreitol improve the oil resistance of polymers can be analyzed mainly from the following aspects: 1. The fluorine atom in trifluoromethylcinnamaldehyde has a high electronegativity, which enables it to form a stronger interaction with other molecules in the polymer, thereby improving the stability and oil resistance of the polymer. It helps to reduce the adsorption and penetration of oil substances on the polymer surface.

[0021] 2. Introducing monomers such as m-trifluoromethylcinnamaldehyde and dithiothreitol into the polymer can form a more compact cross-linked network structure through click chemistry polymerization. This compact cross-linked network structure helps to improve the oil resistance of the polymer.

[0022] 3. Due to the introduction of compounds such as trifluoromethylcinnamaldehyde and dithiothreitol, the surface energy of the polymer will be reduced. Materials with low surface energy are more difficult to be wetted and penetrated by oil substances, thus improving the oil resistance of the polymer. DETAILED DESCRIPTION

[0023] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description in combination with embodiments and comparative examples: Waterproof and oilproof test: Put 100℃ hot water and 150℃ cooking oil in the lunch box respectively, keep the constant temperature for 24 hours, and check whether there is any penetration. The test results are shown in Table 1.

[0024] Hot water permeability test: Test the sample in accordance with the requirements of GB / T 36787-2018. Bend the sample into a bowl shape and place it on a plate lined with filter paper. Pour (95±5)℃ hot water into the sample and let it stand for 30 minutes to observe whether the sample is deformed and whether there is any seepage or leakage on the back of the sample. Water vapor condensation on the bottom due to the temperature difference between the inside and outside of the sample is not considered as seepage or leakage.

[0025] In order to ensure quality, the present invention uses 100°C hot water to maintain a constant temperature for 24 hours for testing.

[0026] Hot oil permeability test: Test the sample in accordance with the requirements of GB / T 36787-2018. Bend the sample into a bowl shape and place it on a flat plate lined with filter paper. Pour (95±5)℃ hot oil into the sample and let it stand for 30 minutes. Observe whether the sample is deformed and whether there is oil print on the back of the sample.

[0027] In order to ensure the quality, the present invention adopts 150° C. edible oil and maintains the constant temperature for 24 hours for testing.

[0028] The experimental lunch boxes measured 22x19x3.5 cm and were divided into 3 compartments.

[0029] Example 1 A method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone, the operating steps of which are as follows: S1: Add 12g methyl acrylate, 10g hydroxyethyl acrylate, 3g dithiothreitol CAS No. 27565-41-9, 0.2g m-trifluoromethylcinnamaldehyde CAS No. 871543-59-8, and 2g triethylamine into a reaction kettle, stir and heat to react; S2: Add 0.05 g of initiator and continue the reaction for 90 min to polymerize the acrylic acid monomer; S3: Continue to add 28g of α,ω-dihydroxypolydimethylsiloxane and continue the reaction to make the silicone linear body and the polymer undergo polymerization reaction; S4: adding 60 g of emulsifier, stirring and mixing to obtain an oil-proofing agent; S5: Add 0.5kg of the oil-proofing agent prepared in S4 to 100kg of lunch box pulp and stir evenly so that the polymer is evenly distributed on the surface of the lunch box pulp to form a dense oil-proof film, which effectively prevents oil stains from adhering.

[0030] The reaction temperature of S1 is 60°C and the reaction time is 90 minutes.

[0031] The initiator is azobisisobutyronitrile.

[0032] The reaction temperature of S3 is 70°C and the reaction time is 150 min.

[0033] The emulsifier is alkyl benzene ether polyoxyethylene ether.

[0034] The reaction temperature of S4 is 50°C and the reaction time is 40 minutes.

[0035] Example 2 A method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone, the operating steps of which are as follows: S1: Add 14g methyl acrylate, 12g hydroxyethyl acrylate, 4g dithiothreitol CAS No. 27565-41-9, 0.3g m-trifluoromethylcinnamaldehyde CAS No. 871543-59-8, and 3g triethylamine into a reaction kettle, stir and heat to react; S2: Add 0.1 g of initiator and continue the reaction for 100 min to polymerize the acrylic acid monomer; S3: Continue to add 32g of α,ω-dihydroxypolydimethylsiloxane and continue the reaction to make the silicone linear body and the polymer undergo polymerization reaction; S4: adding 65 g of emulsifier, stirring and mixing to obtain an oil-proofing agent; S5: Add 0.6kg of the oil-proofing agent prepared in S4 to 100kg of lunch box pulp and stir evenly so that the polymer is evenly distributed on the surface of the lunch box pulp to form a dense oil-proof film, which effectively prevents oil stains from adhering.

[0036] The reaction temperature of S1 is 65°C and the reaction time is 100 min.

[0037] The initiator is dimethyl azobisisobutyrate.

[0038] The reaction temperature of S3 is 75°C and the reaction time is 160 min.

[0039] The emulsifier is fatty alcohol polyoxyethylene ether.

[0040] The reaction temperature of S4 is 55°C and the reaction time is 45 minutes.

[0041] Example 3 A method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone, the operating steps of which are as follows: S1: Add 16g methyl acrylate, 14g hydroxyethyl acrylate, 5g dithiothreitol CAS No. 27565-41-9, 0.4g m-trifluoromethylcinnamaldehyde CAS No. 871543-59-8, and 3g triethylamine into a reaction kettle, stir and heat to react; S2: Add 0.15 g of initiator and continue the reaction for 110 min to polymerize the acrylic acid monomer; S3: Continue to add 34g of α,ω-dihydroxypolydimethylsiloxane and continue the reaction to make the silicone linear body and the polymer undergo polymerization reaction; S4: adding 75 g of emulsifier, stirring and mixing to obtain an oil-proofing agent; S5: Add 0.8kg of the oil-proofing agent prepared in S4 to 100kg of lunch box pulp and stir evenly so that the polymer is evenly distributed on the surface of the lunch box pulp to form a dense oil-proof film, which effectively prevents oil stains from adhering.

[0042] The reaction temperature of S1 is 65°C and the reaction time is 110 min.

[0043] The initiator is azoisobutylcyanamide.

[0044] The reaction temperature of S3 is 75°C and the reaction time is 170 min.

[0045] The emulsifier is PEG-7 coconut oil glyceryl.

[0046] The reaction temperature of S4 is 55°C and the reaction time is 55 min.

[0047] Example 4 A method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone, the operating steps of which are as follows: S1: Add 18g methyl acrylate, 16g hydroxyethyl acrylate, 6g dithiothreitol CAS No. 27565-41-9, 0.5g m-trifluoromethylcinnamaldehyde CAS No. 871543-59-8, and 4g triethylamine into a reaction kettle, stir and heat to react; S2: Add 0.2 g of initiator and continue the reaction for 120 min to polymerize the acrylic acid monomer to form a polymer with good stability and mobility; S3: Continue to add 36g of α,ω-dihydroxypolydimethylsiloxane and continue the reaction to make the silicone linear body and the polymer undergo polymerization reaction; S4: adding 80 g of emulsifier, stirring and mixing to obtain an oil-proofing agent; S5: Add 1kg of the oil-proofing agent prepared in S4 to 100kg of lunch box pulp and stir evenly so that the polymer is evenly distributed on the surface of the lunch box pulp to form a dense oil-proof film, which effectively prevents oil stains from adhering.

[0048] The reaction temperature of S1 is 70°C and the reaction time is 120 min.

[0049] The initiator is azobisisobutylamidine.

[0050] The reaction temperature of S3 is 80°C and the reaction time is 180 min.

[0051] The emulsifier is sodium lauryl sulfate.

[0052] The reaction temperature of S4 is 60°C and the reaction time is 60 min.

[0053] Comparative Example 1 The other steps were the same as in Example 1 except that dithiothreitol and m-trifluoromethylcinnamaldehyde were not added.

[0054] Comparative Example 2 No dithiothreitol was added, and the other steps were the same as in Example 1.

[0055] Comparative Example 3 The other steps were the same as in Example 1 except that m-trifluoromethylcinnamaldehyde was not added.

[0056] Table 1 Waterproof Oil resistance Example 1 No penetration No penetration Example 2 No penetration No penetration Example 3 No penetration No penetration Example 4 No penetration No penetration Comparative Example 1 Obvious penetration Obvious penetration Comparative Example 2 Slight penetration Slight penetration Comparative Example 3 Slight penetration Slight penetration Through the analysis and comparison of the above embodiments and comparative examples, the oil-proof agent prepared by the present invention has good oil-proof performance, can effectively prevent oil stains from adhering, keep food packaging and tableware clean, and improve the use experience.

[0057] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing an oil-proofing agent based on acrylic acid and silicone polymerization, the operating steps of which are: S1: Add 12-18 parts of methyl acrylate, 10-16 parts of hydroxyethyl acrylate, 3-6 parts of dithiothreitol, 0.2-0.5 parts of m-trifluoromethylcinnamaldehyde, and 2-4 parts of triethylamine to a reaction kettle according to weight parts, and stir and heat to react; S2: Add 0.05-0.2 parts of initiator and continue the reaction for 90-120 minutes to polymerize the acrylic acid monomer to form a polymer; S3: Continue to add 28-36 parts of α,ω-dihydroxy polydimethylsiloxane and continue the reaction to make the silicone linear body and the polymer undergo polymerization reaction; S4: Add 60-80 parts of emulsifier, stir and mix to react, and obtain an oil-proofing agent.

2. The method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone according to claim 1, characterized in that: The reaction temperature of S1 is 60-70°C, and the reaction time is 90-120min.

3. The method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone according to claim 1, characterized in that: The initiator is one of azobisisobutyronitrile, dimethyl azobisisobutyrate, azoisobutylcyanoformamide and azobisisobutylamidine.

4. The method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone according to claim 1, characterized in that: The reaction temperature of S3 is 70-80°C, and the reaction time is 150-180min.

5. The method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone according to claim 1, characterized in that: The emulsifier is one of alkyl benzene ether polyoxyethylene ether, fatty alcohol polyoxyethylene ether, fatty acid glyceride polyoxyethylene ether, sodium stearate and sodium lauryl sulfate.

6. The method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone according to claim 1, characterized in that: The reaction temperature of S4 is 50-60°C, and the reaction time is 40-60min.

7. An oil-proofing agent, characterized in that The oil-proofing agent is prepared by the method for preparing an oil-proofing agent based on polymerization of acrylic acid and silicone according to any one of claims 1 to 6.

8. Use of the oil-proofing agent according to claim 7 in preparing pulp, characterized in that: The added amount of the oil-proofing agent is 0.5-1% by mass of the pulp.