阅读说明：本技术 一种抗紫外微球、制备方法及应用 (Uvioresistant microsphere, preparation method and application ) 是由 东为富 刘晓锦 汪洋 李婷 张正 白绘宇 张胜文 马丕明 陈明清 于 2020-12-07 设计创作，主要内容包括：本发明公开了一种抗紫外微球、制备方法及应用,属于高分子材料领域。该微球通过自稳定沉淀聚合制得,共聚体系由给电子单体、受电子单体和反应型紫外吸收剂单体组成。反应结束后通过离心或过滤提纯即可得到微球。所述微球具有优异的广谱紫外吸收效果,聚合过程无需使用任何稳定剂,无需搅拌,溶剂可重复使用,具有较大的经济性,绿色环保。产品可应用于高分子薄膜材料、涂层、纺织品、防晒护肤等领域。(The invention discloses an anti-ultraviolet microsphere, a preparation method and application, and belongs to the field of high polymer materials. The microsphere is prepared by self-stabilizing precipitation polymerization, and a copolymerization system consists of an electron donating monomer, an electron accepting monomer and a reactive ultraviolet absorbent monomer. After the reaction is finished, the microspheres can be obtained by centrifugation or filtration purification. The microsphere has excellent broad-spectrum ultraviolet absorption effect, no stabilizer is needed in the polymerization process, stirring is not needed, the solvent can be repeatedly used, and the microsphere has high economical efficiency and is environment-friendly. The product can be applied to the fields of polymer film materials, coatings, textiles, sun protection, skin care and the like.)

1. The uvioresistant microsphere is characterized in that the microsphere is formed by polymerizing an electron donating monomer, an electron accepting monomer and a reactive ultraviolet absorbent monomer in a solvent through an initiator; wherein the molar ratio of the electron donor monomer, the electron acceptor monomer and the reactive ultraviolet absorbent monomer is 100 (40-99.5) to 0.5-60; the mass of the initiator is 0.05 to 5 weight percent of the total mass of the three monomers; the reactive ultraviolet absorbent monomer contains a chromophoric group and a chromophoric group with conjugated structures and a carbon-carbon double bond structure capable of participating in polymerization reaction.

2. The UV-resistant microsphere of claim 1, wherein the molar ratio of the electron donor monomer, the electron acceptor monomer and the reactive UV absorber monomer is 100 (80-99) to (1-20); the mass of the initiator is 1-3 wt% of the total mass of the three monomers.

3. The UV-resistant microsphere according to claim 1, wherein the particle size of the microsphere is between 230 nm and 810 nm.

4. The UV resistant microsphere of claim 1, wherein the electron donor monomer is one or a combination of two or more of vinyl acetate, styrene, α -methylstyrene, α -ethylstyrene, 4-ethylstyrene, p-methoxystyrene, p-methylstyrene, isoprene, allylbenzene, vinyltoluene, cyclopentadiene, dicyclopentadiene, methylcyclopentadiene, methyldicyclopentadiene, dihydrodicyclopentadiene, dihydrodimethyldicyclopentadiene, indene, methylindene, 2, 3-dihydrofuran, benzofuran, methylbenzofuran, and methyl methacrylate;

the electron accepting monomer is one or the combination of more than two of maleic anhydride, maleimide and derivatives thereof, itaconic anhydride and alpha-methylene-gamma-butyrolactone;

the initiator in the reaction system is one or the combination of more than two of organic peroxide or azo compounds;

the solvent in the reaction system is one or the combination of more than two of organic acid alkyl ester, mixed solution of organic acid alkyl ester and alkane, toluene and xylene; wherein the structural general formula of the organic acid alkyl ester is as follows:

wherein R is₃Is H, C1-C8 alkyl, benzyl, phenyl or substituted phenyl; r₄Is C1-C8 alkyl.

5. The UV-resistant microsphere according to claim 4, wherein the reactive UV absorber monomer has the following structure:

wherein R is hydrogen or methyl, R₁Is hydrogen or methyl, R₂Is hydrogen or methyl, X is a group which can absorb ultraviolet rays;

the azo initiator is one or two of azodiisobutyronitrile and azodiisoheptonitrile; the organic peroxide initiator is one or the combination of more than two of dibenzoyl peroxide, lauroyl peroxide, tolytidine peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane, 2-di (tert-butylperoxy) butane, 2-di (tert-butylperoxy) octane, n-butyl-4, 4-bis (tert-butylperoxy) valerate, bis (4-tert-butylcyclohexyl) peroxydicarbonate, di-n-propyl peroxydicarbonate, bis (3-methyl-3-methoxybutyl peroxydicarbonate), tert-butyl peroxybenzoate, tert-butyl peroxyvalerate, diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate;

the organic acid alkyl ester is one or a mixture of more than two of ethyl acetate, butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, benzyl acetate, phenyl acetate, ethyl butyrate, isoamyl butyrate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, methyl phenylacetate, ethyl phenylacetate, propyl phenylacetate, butyl phenylacetate and isoamyl phenylacetate;

the volume fraction of alkane in the mixed solution of organic acid alkyl ester and alkane is 5-50%; wherein the alkane is n-pentane, cyclohexane, n-hexane, n-heptane or n-octane.

6. The UV-resistant microsphere according to claim 5, wherein the UV-absorbing group X is benzotriazole, benzophenone or triazine; the volume fraction of the alkane in the mixed solution of the organic acid alkyl ester and the alkane is 10-40%.

7. The UV-resistant microsphere according to claim 6, wherein the UV-absorbing group X is one or a combination of two or more of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole, 2- (2 '-hydroxy-4' -acrylate phenyl) -2H-benzotriazole, 2-hydroxy-4- (3-methacrylate-2-hydroxypropoxy) benzophenone, and 2-hydroxy-4-methacrylate benzophenone.

8. The method for preparing uvioresistant microspheres according to any one of claims 1 to 7, wherein the preparation method is a self-stabilizing precipitation polymerization method, and comprises the following steps:

(1) adding an electron donor monomer, an electron acceptor monomer, a reactive ultraviolet absorbent monomer and an initiator into a solvent, ultrasonically dissolving, and uniformly mixing to obtain a reaction system, wherein the total monomer concentration of the reaction system is 0.25-3 mol/L;

(2) the reaction system is reacted for 1 to 12 hours at the temperature of between 50 and 100 ℃ under the protection of inert gas to obtain a stable microsphere dispersion system;

(3) purifying the microspheres by centrifugation or filtration, and drying to obtain the microspheres with broad-spectrum ultraviolet absorptivity.

9. The preparation method according to claim 1, wherein the total monomer concentration of the reaction system in the step (1) is 0.5mol/L to 2 mol/L; the reaction time of the step (2) is 6-8 h.

10. The use of UV-resistant microspheres according to any one of claims 1 to 7, wherein said microspheres with broad-spectrum UV-absorbing properties are used in the fields of polymeric film materials, coatings, textiles or sun protection and skin care.

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to a method for preparing microspheres with broad-spectrum ultraviolet absorptivity by self-stabilization precipitation polymerization.

Background

The sunlight contains 5% of ultraviolet light, 46% of visible light and 49% of infrared light. Although a small portion of the sun's rays, excessive exposure to ultraviolet light not only causes many adverse effects to human health such as sunburn, accelerated skin photoaging and various skin cancers, but also causes decomposition and degradation of organic compounds, discoloration of dyes and pigments, and impaired mechanical properties of polymers and plastics. Therefore, it is necessary to develop a highly efficient uv absorbing material to avoid the adverse effects of uv radiation.

At present, two main types of ultraviolet absorbers are available, namely inorganic metal oxides or organic micromolecular ultraviolet absorbers. Inorganic metal oxides such as TiO₂、ZnO、SiO₂、CeO₂Ultraviolet radiation is attenuated by reflecting, scattering and absorbing ultraviolet light and is often used to make photo-protective materials. However, these inorganic particles tend to exhibit photocatalytic properties after absorbing ultraviolet rays, and accelerate photodegradation of polymers. Common organic micromolecular ultraviolet absorbers such as benzophenone, cinnamic acid, triazine, camphor derivatives, p-aminobenzoic acid derivatives and the like have poor light stability, are easy to migrate and have potential safety hazards, and most of ultraviolet absorbers have narrow ultraviolet absorption. Papers ACS Materials Letters2019,1(3) 336-. Paper ACS apple Mater Interfaces2016,8(48):3265532660 preparation of nanoparticles with broad-spectrum ultraviolet absorptivity by encapsulating three small-molecule ultraviolet absorbers with different absorption bands in ethyl cellulose is complicated and not suitable for large-scale production. The self-stabilization precipitation polymerization method does not need to use any stabilizer or stirring, the solvent can be repeatedly used, and the method has the advantages of high economical efficiency, environmental friendliness and suitability for industrial production. The patent No. CN201710659517.5 uses styrene, maleic anhydride and acrylic ester as monomers to prepare multi-copolymer micro-nano particles by a self-stabilizing precipitation polymerization method, and the purpose of introducing a third monomer of acrylic ester is to reduce copolymer T_gAnd the water resistance is improved. The patent No. CN201910742812.6 utilizes self-stabilization precipitation polymerization technology to prepare styrene-maleic anhydride-acrylamide multipolymer microspheres, and the multipolymer microspheres after the acrylamide containing polar groups is introduced can be used as pour point depressants of crude oil. However, a method for preparing copolymer microspheres with broad spectrum ultraviolet absorptivity by self-stabilization precipitation polymerization with organic acid esters as a solvent and a reactive ultraviolet absorbent as a third monomer has not been reported so far.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides the uvioresistant microsphere and the preparation method thereof, which have the advantages of no need of using any stabilizer or stirring, simple operation, reusable solvent, economy, environmental protection and suitability for industrial production.

The technical scheme of the invention is as follows:

an anti-ultraviolet microsphere is formed by polymerizing an electron donor monomer, an electron acceptor monomer and a reactive ultraviolet absorber monomer in a solvent through an initiator; wherein the molar ratio of the electron donor monomer, the electron acceptor monomer and the reactive ultraviolet absorbent monomer is 100 (40-99.5) to (0.5-60), preferably 100 (80-99) to (1-20); the mass of the initiator is from 0.05 to 5% by weight, preferably from 1 to 3% by weight, based on the total mass of the three monomers.

The electron donor monomer is one or the combination of more than two of vinyl acetate, styrene, alpha-methylstyrene, alpha-ethylstyrene, 4-ethylstyrene, p-methoxystyrene, p-methylstyrene, isoprene, allyl benzene, vinyl toluene, cyclopentadiene, dicyclopentadiene, methylcyclopentadiene, methyldicyclopentadiene, dihydrodicyclopentadiene, dihydromethyldimethylcyclopentadiene, indene, methylindene, 2, 3-dihydrofuran, benzofuran, methylbenzofuran and methyl methacrylate, preferably one or the combination of more than two of vinyl acetate, styrene, alpha-methylstyrene, alpha-ethylstyrene, 4-ethylstyrene, p-methoxystyrene and p-methylstyrene.

The electron accepting monomer is one or a combination of more than two of maleic anhydride, maleimide and derivatives thereof, itaconic anhydride and alpha-methylene-gamma-butyrolactone, and one or a combination of more than two of maleic anhydride and itaconic anhydride is preferable.

The reactive ultraviolet absorbent monomer contains a chromophoric group and a chromophoric group with conjugated structures and a carbon-carbon double bond structure capable of participating in polymerization reaction, and can be of the following structures:

wherein R is hydrogen or methyl, R₁Is hydrogen or methyl, R₂Hydrogen or methyl, X is a group which absorbs ultraviolet rays, such as benzotriazole, benzophenone, triazine and the like, and further, 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] ethyl]Phenyl radical]One or the combination of more than two of-2H-benzotriazole, 2- (2 '-hydroxy-4' -acrylate phenyl) -2H-benzotriazole, 2-hydroxy-4- (3-methacrylate-2-hydroxypropoxy) benzophenone and 2-hydroxy-4-methacrylate benzophenone.

The initiator in the reaction system is one or the combination of more than two of organic peroxide or azo compounds; the azo initiator is one or two of azodiisobutyronitrile, azodiisoheptonitrile and the like; the organic peroxide initiator is one or the combination of more than two of dibenzoyl peroxide, lauroyl peroxide, tolytidine peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane, 2-di (tert-butylperoxy) butane, 2-di (tert-butylperoxy) octane, n-butyl-4, 4-bis (tert-butylperoxy) valerate, bis (4-tert-butylcyclohexyl) peroxydicarbonate, di-n-propyl peroxydicarbonate, bis (3-methyl-3-methoxybutyl peroxydicarbonate), tert-butyl peroxybenzoate, tert-butyl peroxyvalerate, diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate.

The solvent in the reaction system is one or the combination of more than two of organic acid alkyl ester, mixed solution of organic acid alkyl ester and alkane, toluene and xylene; wherein the structural general formula of the organic acid alkyl ester is as follows:

wherein R is₃Is H, C1-C8 alkyl, benzyl, phenyl or substituted phenyl; r₄Is C1-C8 alkyl; further, the organic acid alkyl ester is one or a mixture of two or more of ethyl acetate, butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, benzyl acetate, phenyl acetate, ethyl butyrate, isoamyl butyrate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, methyl phenylacetate, ethyl phenylacetate, propyl phenylacetate, butyl phenylacetate and isoamyl phenylacetate, and preferably one or a combination of two or more of isoamyl acetate, benzyl acetate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate and isoamyl benzoate.

The volume fraction of the alkane in the mixed solution of the organic acid alkyl ester and the alkane is 5-50%, preferably 10-40%; the alkane is n-pentane, cyclohexane, n-hexane, n-heptane or n-octane, preferably n-heptane.

A preparation method of uvioresistant microspheres is a self-stabilizing precipitation polymerization method and comprises the following steps:

(1) adding an electron donor monomer, an electron acceptor monomer, a reactive ultraviolet absorbent monomer and an initiator into a solvent, ultrasonically dissolving, and uniformly mixing to obtain a reaction system, wherein the total monomer concentration of the reaction system is 0.25-3 mol/L, preferably 0.5-2 mol/L;

(2) the reaction system is reacted for 1 to 12 hours, preferably 6 to 8 hours at the temperature of between 50 and 100 ℃ under the protection of inert gas to obtain a stable microsphere dispersion system;

(3) purifying the microspheres by centrifugation or filtration, and drying to obtain the microspheres with broad-spectrum ultraviolet absorptivity.

The microsphere with broad-spectrum ultraviolet absorptivity can be used in the fields of polymer film materials, coatings, textiles, sun protection, skin care and the like.

The particle size of the microsphere is between 230 and 810 nm.

The invention has the beneficial effects that:

(1) the microspheres with broad spectrum ultraviolet absorptivity are prepared by adopting a self-stabilization precipitation polymerization method, no stabilizer or dispersant is required to be added, the obtained polymer is easy to separate, the solvent can be recycled, and most of the used solvent is low-toxicity organic acid alkyl ester and alkane;

(2) the self-stabilization precipitation polymerization technology adopted by the invention is simple to operate and low in cost, and the prepared polymer microspheres have pure surfaces and uniform particle sizes and are suitable for industrial production;

(3) the microsphere with broad-spectrum ultraviolet absorptivity is obtained by copolymerizing a reactive ultraviolet absorbent monomer, an electron donor monomer and an electron acceptor monomer, namely, the ultraviolet absorbent is bonded to the copolymer microsphere, so that the problems that a small-molecular ultraviolet absorbent in the prior art is unstable and is easy to migrate from particles are solved.

Drawings

FIG. 1 is an infrared spectrum of the copolymer microsphere prepared in example 4.

FIG. 2 is a scanning electron micrograph of copolymer microspheres prepared in example 4.

FIG. 3 is a graph showing UV absorption spectra of copolymer microspheres prepared in example 4 and comparative example 1.

Detailed description of the invention

The present invention will be further described with reference to the following examples.

Example 1

Using ethyl benzoate as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.039g of initiator azobisisobutyronitrile into 40mL of ethyl benzoate, and performing ultrasonic treatment to fully dissolve the materials so as to uniformly mix the materials, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the dosage of the initiator is 1 wt% of the total mass of the monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing and centrifuging for three times, and drying in vacuum to constant weight to obtain the microspheres 1, wherein the particle sizes are listed in Table 1.

Example 2

Using dimethylbenzene as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.039g of initiator azobisisobutyronitrile in 40mL of dimethylbenzene, and performing ultrasonic treatment to fully dissolve the materials so as to uniformly mix the materials, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the dosage of the initiator is 1 wt% of the total mass of monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain microspheres 2, wherein the particle sizes are listed in Table 1.

Example 3

Using ethyl benzoate/n-heptane (volume ratio 9:1) as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.039g of azodiisobutyronitrile serving as an initiator in 40mL of the solvent, fully dissolving the mixture by ultrasonic treatment to mix the mixture uniformly, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the amount of the initiator is 1 wt% of the total mass of the monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain microspheres 3, wherein the particle sizes are listed in Table 1.

Example 4

Using ethyl benzoate/n-heptane (volume ratio is 7:3) as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.039g of azodiisobutyronitrile serving as an initiator in 40mL of the solvent, fully dissolving the mixture by ultrasonic treatment to mix the mixture uniformly, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the amount of the initiator is 1 wt% of the total mass of monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain microspheres 4, wherein the particle sizes are listed in Table 1.

Example 5

Using ethyl benzoate/n-heptane (volume ratio is 5:5) as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.039g of azodiisobutyronitrile serving as an initiator in 40mL of the solvent, fully dissolving the mixture by ultrasonic treatment to mix the mixture uniformly, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the amount of the initiator is 1 wt% of the total mass of monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the microspheres 5, wherein the particle sizes are listed in Table 1.

Example 6

Using ethyl benzoate/n-heptane (volume ratio is 7:3) as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.94g of maleic anhydride, 0.06g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.037g of azodiisobutyronitrile serving as an initiator in 40mL of the solvent, fully dissolving the mixture by ultrasonic treatment to mix the mixture uniformly, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:99:1, the amount of the initiator is 1 wt% of the total mass of the monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain microspheres 6, wherein the particle sizes are listed in Table 1.

Example 7

Using ethyl benzoate/n-heptane (volume ratio is 7:3) as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.82g of maleic anhydride, 0.45g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.040g of azodiisobutyronitrile as an initiator in 40mL of the solvent, fully dissolving the components by ultrasonic treatment to mix the components uniformly, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:93:7, the dosage of the initiator is 1 wt% of the total mass of monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain microspheres 7, wherein the particle sizes are listed in Table 1.

Example 8

Using ethyl benzoate/n-heptane (volume ratio is 7:3) as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.078g of azodiisobutyronitrile serving as an initiator in 40mL of the solvent, fully dissolving the mixture by ultrasonic treatment to mix the mixture uniformly, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the amount of the initiator is 2 wt% of the total mass of monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the microspheres 8, wherein the particle sizes are listed in Table 1.

Example 9

Using ethyl benzoate/n-heptane (volume ratio is 7:3) as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.117g of azodiisobutyronitrile serving as an initiator in 40mL of the solvent, fully dissolving the mixture by ultrasonic treatment to mix the mixture uniformly, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the dosage of the initiator is 3 wt% of the total mass of monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the microspheres 9, wherein the particle sizes are listed in Table 1.

Example 10

Using ethyl benzoate/n-heptane (volume ratio is 7:3) as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.039g of azodiisobutyronitrile serving as an initiator in 80mL of the solvent, fully dissolving the mixture by ultrasonic treatment to mix the mixture uniformly, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the dosage of the initiator is 1 wt% of the total mass of monomers, and the concentration of the total monomers is 0.5 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the microspheres 10, wherein the particle sizes are listed in Table 1.

Example 11

Using ethyl benzoate/n-heptane (volume ratio is 7:3) as a solvent of a reaction system, dissolving 2.08g of styrene, 1.86g of maleic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.043g of azodiisobutyronitrile serving as an initiator in 40mL of the solvent, fully dissolving the mixture by ultrasonic treatment to mix the mixture uniformly, wherein the molar ratio of the styrene to the maleic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the amount of the initiator is 1 wt% of the total mass of the monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the microspheres 11, wherein the particle sizes are listed in Table 1.

Example 12

Isoamyl acetate is used as a solvent of a reaction system, 2.08g of styrene, 2.13g of itaconic anhydride, 0.32g of 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and 0.045g of initiator azobisisobutyronitrile are dissolved in 40mL of solvent, the mixture is fully dissolved by ultrasonic to be uniformly mixed, the molar ratio of the styrene to the itaconic anhydride to the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole in the reaction system is 100:95:5, the dosage of the initiator is 1 wt% of the total mass of the monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the microspheres 12, wherein the particle sizes are listed in Table 1.

Example 13

Taking isoamyl benzoate as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.36g of 2-hydroxy-4- (3-methacrylate-2-hydroxypropoxy) benzophenone and 0.039g of initiator azobisisobutyronitrile in 40mL of solvent, and ultrasonically dissolving the two components to uniformly mix the two components, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2-hydroxy-4- (3-methacrylate-2-hydroxypropoxy) benzophenone in the reaction system is 100:95:5, the dosage of the initiator is 1 wt% of the total mass of monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the microspheres 13, wherein the particle sizes are listed in Table 1.

Example 14

Taking isoamyl benzoate as a solvent of a reaction system, dissolving 1.72g of vinyl acetate, 1.86g of maleic anhydride, 0.36g of 2-hydroxy-4- (3-methacrylate-2-hydroxypropoxy) benzophenone and 0.039g of initiator dibenzoyl peroxide in 40mL of the solvent, and ultrasonically dissolving the two components to uniformly mix the two components, wherein the molar ratio of the vinyl acetate to the maleic anhydride to the 2-hydroxy-4- (3-methacrylate-2-hydroxypropoxy) benzophenone in the reaction system is 100:95:5, the dosage of the initiator is 1 wt% of the total mass of the monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 90 ℃ for 6h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the microspheres 14, wherein the particle sizes are listed in Table 1.

Comparative example 1

Dissolving 1.72g of vinyl acetate, 1.96g of maleic anhydride and 0.037g of initiator azobisisobutyronitrile into 40mL of isoamyl acetate by taking isoamyl acetate as a solvent of a reaction system, and fully dissolving the components by ultrasonic treatment to uniformly mix, wherein the molar ratio of the vinyl acetate to the maleic anhydride in the reaction system is 1:1, the initiator accounts for 1 wt% of the total mass of the monomers, and the total monomer concentration is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product at 8000 rpm for 5min, adding petroleum ether, washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the vinyl acetate-maleic anhydride microspheres, wherein the particle sizes are listed in Table 1.

Comparative example 2

Dissolving 2.08g of styrene, 1.57g of maleic anhydride, 0.51g of butyl acrylate and 0.042g of initiator azobisisobutyronitrile into 40mL of isoamyl acetate by taking isoamyl acetate/n-heptane (volume ratio is 5:1) as a solvent, and fully dissolving the components by ultrasonic treatment to uniformly mix the components, wherein the molar ratio of the styrene to the maleic anhydride to the butyl acrylate in a reaction system is 100:80:20, the dosage of the initiator is 1 wt% of the total mass of the monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the styrene-maleic anhydride-butyl acrylate microspheres, wherein the particle sizes are listed in Table 1.

Comparative example 3

Dissolving 2.08g of styrene, 1.57g of maleic anhydride, 0.28g of acrylamide and 0.039g of azodiisobutyronitrile serving as an initiator in 40mL of isoamyl acetate by taking isoamyl acetate as a solvent, and sufficiently dissolving the components by ultrasonic treatment to uniformly mix the components, wherein the molar ratio of the styrene to the maleic anhydride to the acrylamide in a reaction system is 100:80:20, the dosage of the initiator is 1 wt% of the total mass of the monomers, and the concentration of the total monomers is 1 mol/L; introducing nitrogen into the system for 30min, reacting at 75 ℃ for 8h, after the reaction is finished, centrifugally separating the reaction product for 10min at the rotating speed of 12000 r/min, adding petroleum ether for washing, centrifuging for three times, and drying in vacuum to constant weight to obtain the styrene-maleic anhydride-acrylamide microspheres, wherein the particle sizes are listed in Table 1.

Ultraviolet absorption test

Has broad-spectrum ultraviolet absorptivity microsphere, and ultraviolet absorptivity test. Double-beam uv-vis spectrophotometer (TU-1901, beijing prosperous instruments ltd): the absolute methanol is used as a solvent and a reference solution, the concentration of a sample to be detected is 0.05mg/mL, the scanning range is 200-400nm, and the scanning interval is 1 nm. The microspheres can be found to have stronger absorption capacity to ultraviolet light within the range of 200-400nm, namely have broad-spectrum ultraviolet absorption performance. The samples prepared in examples 1 to 14 and comparative examples 1 to 3 were subjected to the ultraviolet absorption test, and the results are shown in Table 1, and the ultraviolet absorption spectra of the samples in example 4 and comparative example 1 are shown in FIG. 3.

TABLE 1

The particle size of the uvioresistant microsphere is 230-810nm, and the microspheres in examples 1-14 have excellent absorption to UVC (200-280nm), UVB (280-320nm) and UVA (320-400nm), which shows that the microsphere prepared by the invention has excellent broad-spectrum ultraviolet absorptivity; the copolymer microspheres prepared in comparative examples 1-3 only absorb UVC light well, and have poor absorption effects on UVB and UVA light. By comparison, the addition of the reactive ultraviolet absorbent monomer widens the ultraviolet absorption range of the copolymer microspheres, so that the embodiment of the application has more excellent broad-spectrum ultraviolet absorption performance compared with a comparative example.

According to the broad-spectrum ultraviolet absorbent microsphere, the ultraviolet absorbent is bonded to the polymer microsphere, so that the problems that the micromolecule ultraviolet absorbent is unstable, easy to decompose, narrow in absorption, easy to migrate from particles and the like are solved, and the application of the broad-spectrum ultraviolet absorbent microsphere in different fields is widened; the microsphere is synthesized by a self-stabilization precipitation polymerization technology, a stabilizer is not required to be used, stirring is not required, a solvent can be recycled, the synthesis process is simple and convenient, the cost is low, and the microsphere is suitable for large-scale industrial production.

Those of ordinary skill in the art will understand that: the invention is not to be considered as limited to the specific embodiments thereof, but is to be understood as being modified in all respects, all changes and equivalents that come within the spirit and scope of the invention.