Acrylic acid quadripolymer as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to an acrylic acid quadripolymer and a preparation method and application thereof.The method comprises the steps that EA, BA, VA and AM monomers are mixed in sequence and stirred till the system is clear and transparent, and a mixed solution A is obtained; weighing an initiator, an emulsifier, ethanol and deionized water according to a ratio, sequentially adding into a dry three-neck flask with a stirring paddle, and continuously stirring at a rotating speed of 200-300r / min at room temperature for 15-20min until the system is uniform and transparent, so as to obtain a mixed solution B; dropwise adding the mixed solution A into the mixed solution B at a constant speed under the condition of 50-80 DEG C to carry out polymerization reaction, wherein the dropwise adding time is controlled within 1.5-2.5 hours; and after dropwise adding is completed, firstly raising the temperature to 60-67 DEG C to enable the solution to flow back, then uniformly emulsifying the reaction system to obtain white emulsion, and finally cooling to 50 DEG C and discharging.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to an acrylic tetromer, its preparation method, and its application. Background Technology

[0002] Currently, most copolymer adhesives in the biomedical field are concentrated in ternary or lower systems: (1) Research on low-allergenic / high-permeability acrylate adhesives: Research teams represented by Zhejiang University and South China University of Technology are committed to preparing pressure-sensitive adhesives with low skin irritation by copolymerizing soft monomers such as isooctyl acrylate (2-EHA) and butyl acrylate (BA) and introducing functional monomers (such as acrylic acid (AA)) to adjust the cohesive strength. However, these traditional formulations still rely heavily on petroleum-based monomers, and in order to achieve sufficient cohesive strength, it is often necessary to introduce crosslinking agents or increase the acrylic acid content, which leads to hardening of the adhesive layer, decreased permeability, or skin discomfort caused by residual small molecules after long-term use. (2) Research on hydrophilic / hydrocolloid skin adhesives: Shanghai Jiaotong University, Donghua University and other institutions have studied the introduction of hydrophilic monomers such as hydroxyethyl acrylate (HEA) and N-vinylpyrrolidone (NVP) into acrylate systems for wound dressing adhesives to absorb exudate and maintain a moist environment. Such research is more common in the field of hydrogel dressings. However, hydrophilic monomers usually lead to a significant decrease in the wet tack of the colloidal material, and the monomers and solvents (such as ethyl acetate) remaining in the traditional polymerization process pose a potential risk to open wounds. (3) Exploration of bio-based / degradable acrylate adhesives: Teams such as Beijing University of Chemical Technology have tried to partially replace petroleum-based monomers with itaconic acid, lactic acid derivative monomers, etc., or to modify them by blending with natural polymers such as starch and cellulose. However, bio-based monomers often have a large difference in reactivity from petroleum-based monomers, making it difficult to achieve precise sequence control in copolymerization, resulting in unstable adhesive properties (especially holding power and repeated adhesion), which is still far from meeting the mechanical and comfort requirements for long-term / repeated adhesion to human skin. Therefore, there is an urgent need for a copolymer adhesive that can simultaneously meet the requirements of "green and environmentally friendly preparation" and "skin affinity". Summary of the Invention

[0003] The purpose of this invention is to provide an acrylic tetromer, its preparation method, and its application, in order to solve the above-mentioned problems existing in the prior art.

[0004] The present invention specifically adopts the following solution: A method for preparing an acrylic tetromer includes the following steps: S1. Mix the four monomers, namely ethyl acrylate (EA), butyl acrylate (BA), vinyl acetate (VA) and acrylamide (AM), in sequence and stir until the system is clear and transparent to obtain mixed solution A; S2. Weigh out the initiator, emulsifier, ethanol and deionized water in proportion, and add them sequentially to a dry three-necked flask with a stirrer. Stir continuously at 200-300 r / min for 15-20 min at room temperature until the system is homogeneous and transparent to obtain mixed solution B. S3. Mixed solution A is added dropwise to mixed solution B at a constant rate under conditions of 50-80 degrees Celsius to carry out the polymerization reaction, and the dropping time is controlled within 1.5-2.5 hours; S4. After the addition is complete, raise the temperature to 60-67 degrees Celsius to reflux the solution. Then, the reaction system will undergo uniform emulsification to obtain a white emulsion. Finally, cool down to 50 degrees Celsius to discharge the material.

[0005] Further, the proportion of the four monomers in the S1 mixed solution A by molar amount is ethyl acrylate: butyl acrylate: vinyl acetate: acrylamide = (0.71~2.14): (1.0~3.0): (0.01~3.04): (0.50~1.50).

[0006] Furthermore, the ratio of ethanol to deionized water in the S2 mixed solution B, by molar amount, is (0.5-1):(2-3.5).

[0007] Furthermore, the initiator in S2 is selected as ammonium persulfate or sodium persulfate, and its amount accounts for 0.5% to 1.5% of the total amount of mixed solution B by molar amount.

[0008] Furthermore, the emulsifier in S2 is selected from polyoxyethylene alkylphenol ether or sodium dodecyl sulfate, and its amount accounts for 0.01% to 5% of the total amount of mixed solution B by molar amount.

[0009] An acrylic tetromer prepared by any of the above methods has the following structural formula: .

[0010] An application of an acrylic tetromer as described above as an environmentally friendly human skin adhesive.

[0011] The beneficial effects of this invention are as follows: This invention achieves a gradient sequence distribution of polymer chains by precisely controlling the polymerization rate and feeding order of the quaternary monomers. This results in copolymers possessing excellent initial tack, the ability to be repeatedly peeled and stuck without leaving residue, high moisture permeability, and active moisturizing and anti-allergic functions. The copolymer exhibits good adhesion, is non-toxic and odorless, has a fast curing time, and produces a well-formed, transparent film with strong adhesion after curing. It is non-irritating and non-allergenic to the skin, resistant to human sweat, easy to clean, and can be rinsed with water without leaving any residue on the skin.

[0012] 1. Controlling polymerization reaction conditions Reaction temperature: Temperature affects the activity of free radicals, thereby altering the monomer copolymerization rate. This invention experimentally determined an optimal temperature range of 50-80℃ to minimize the difference in copolymerization rates, which is beneficial for uniform monomer copolymerization.

[0013] Initiator type and concentration: Select a suitable initiator (such as ammonium persulfate or azobisisobutyronitrile). The decomposition rate and free radical type of different initiators will affect the monomer polymerization activity. Control the initiator concentration. Low concentration of initiator can slow down the polymerization rate and reduce compositional drift caused by differences in reactivity ratio.

[0014] 2. Optimize the individual feeding method Semi-continuous dripping method: Based on the difference in monomer reactivity ratio, calculate and prepare a monomer mixture with the same composition as the copolymer, and add it to the reaction system by constant dripping to avoid uneven product composition caused by preferential polymerization of monomers with high reactivity ratio.

[0015] Batch addition method: For monomers with large differences in polymerization reactivity (such as acrylamide and vinyl acetate), monomers with low polymerization reactivity are added in batches to compensate for their slow polymerization rate and maintain a stable monomer concentration ratio in the system.

[0016] 3. Adjust the copolymerization system environment Emulsification / dispersion system control: Select a suitable emulsifier (such as sodium dodecyl sulfate) and adjust the effective polymerization rate of monomers by controlling the micelle concentration and changing the distribution ratio of monomers in micelles and aqueous phase. Attached Figure Description

[0017] Figure 1 This is the copolymer finally prepared in this invention. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0019] This invention discloses a method for preparing an acrylic tetromer, comprising the following steps: S1. Mix the four monomers, ethyl acrylate (EA), butyl acrylate (BA), vinyl acetate (VA), and acrylamide (AM), in the following order: (0.71–2.14): (1.0–3.0): (0.01–3.04): (0.50–1.50). Turn on the stirrer and stir until the system is clear and transparent to obtain mixed solution A. S2. Weigh out the initiator (ammonium persulfate or sodium persulfate), emulsifier (polyoxyethylene alkylphenol ether or sodium dodecyl sulfate), ethanol, and deionized water in proportion (0.5-1):(2-3.5). Add them sequentially to a dry three-necked flask equipped with a stirrer. Stir continuously at 200-300 r / min for 15-20 min at room temperature until the system is homogeneous and transparent to obtain mixed solution B. The initiator accounts for 0.5%-1.5% of the total amount of mixed solution B, and the emulsifier accounts for 0.01%-5% of the total amount of mixed solution B.

[0020] S3. Mixed solution A is added dropwise to mixed solution B at a constant rate under conditions of 50-80 degrees Celsius to carry out the polymerization reaction, and the dropping time is controlled within 1.5-2.5 hours; S4. After the addition is complete, first raise the temperature to 60-67 degrees Celsius to reflux the solution. Then, the reaction system undergoes homogeneous emulsification to obtain a white emulsion. Finally, lower the temperature to 50 degrees Celsius to discharge the material, ultimately obtaining the following: Figure 1 The copolymer shown.

[0021] The quaternary copolymer prepared above can be used as an environmentally friendly human skin adhesive.

[0022] The above description is merely a preferred embodiment of the present invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A process for the preparation of an acrylic acid tetrapolymer, characterized in that, The method comprises the following steps: S1. mixing ethyl acrylate EA, butyl acrylate BA, vinyl acetate VA and acrylamide AM in sequence, stirring until the system is clear and transparent to obtain a mixed solution A; S2. weighing initiators, emulsifiers, ethanol and deionized water according to the proportion, adding them into a dry three-necked flask with a stirring paddle in sequence, continuously stirring at a speed of 200-300 r / min at room temperature for 15-20 min until the system is uniform and transparent to obtain a mixed solution B; S3. uniformly dropping the mixed solution A into the mixed solution B at a speed of 50-80 degrees Celsius to carry out a polymerization reaction, and controlling the dropping time to be 1.5-2.5 hours; S4. after the dropping is completed, first increasing the temperature to 60-67 degrees Celsius to make the solution reflux, then uniformly emulsifying the reaction system to obtain a white emulsion, and finally cooling to 50 degrees Celsius to discharge.

2. The process for the preparation of an acrylic terpolymer according to claim 1, characterized in that: In the mixed solution A of S1, the proportion of the four monomers is ethyl acrylate: butyl acrylate: vinyl acetate: acrylamide = (0.71-2.14): (1.0-3.0): (0.01-3.04): (0.50-1.50) in terms of the amount of substance.

3. The method of making an acrylic terpolymer according to claim 1, characterized in that: In the mixed solution B of S2, the proportion of ethanol and deionized water is (0.5-1): (2-3.5) in terms of the amount of substance.

4. The method of making an acrylic terpolymer according to claim 1, characterized in that: In S2, the initiator is ammonium persulfate or sodium persulfate, and the amount of the initiator accounts for 0.5%-1.5% of the total amount of the mixed solution B in terms of the amount of substance.

5. The method of making an acrylic terpolymer according to claim 1, wherein: In S2, the emulsifier is polyoxyethylene alkyl phenol ether or sodium dodecyl sulfate, and the amount of the emulsifier accounts for 0.01%-5% of the total amount of the mixed solution B in terms of the amount of substance.

6. An acrylic acid quaternary copolymer prepared by the preparation method of any one of claims 1-5, and the structural formula is as follows: 。 7. Application of the acrylic acid quaternary copolymer of claim 6 as an environmentally friendly human skin adhesive.

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