Preparation method of monodisperse solvent-proof high-carboxyl-content polystyrene microsphere

Abstract

The invention provides a preparation method of a monodisperse solvent-proof high-carboxyl-content polystyrene microsphere. The preparation method comprises the following steps: taking styrene as a main polymerization monomer, ethyl methacrylate and tert-butyl methacrylate as comonomers, divinyl benzene, vinytriethoxylsilane and diacetone acrylamide as crosslinking agents, trimethylolpropane as a chain extender, and sodium bisulfite as an acrylic ester solubilizer, then the monodisperse solvent-proof high-carboxyl-content polystyrene microsphere is prepared through a soap-free emulsion polymerization reaction, adding styrene, divinyl benzene, trimethylolpropane and deionized water in a 250 mL three-neck flask during preparation, introducing N2, stirring for 30 min at a high speed, adding diacetone acrylamide, ethyl methacrylate, tert-butyl methacrylate and sodium hydrogen sulfite, heating to 70-85 DEG C, adding an initiator, namely potassium persulfate, and reacting for 6-24 hours. Thepreparation method can be used for preparing the monodisperse solvent-proof high-carboxyl-content size-controllable polystyrene microsphere.

Description

technical field [0001] The invention belongs to the technical field of soap-free emulsion polymerization, and relates to a preparation method of monodisperse solvent-resistant high-surface carboxyl polystyrene microspheres. Background technique [0002] Emulsion polymerization is an important method for preparing monodisperse polystyrene microspheres. The prepared microspheres have high particle size uniformity and good shape integrity. However, due to the addition of emulsifiers during the reaction and the emulsifiers are difficult to remove after the reaction , so that it is subject to various restrictions in the application of many biomedical fields. In view of this, soap-free emulsion polymerization has developed rapidly. [0003] Soap-free emulsion polymerization refers to the emulsion polymerization process in which no emulsifier is mixed at all or only a small amount of emulsifier (its concentration is lower than the critical micelle concentration CMC) is added in the...

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Problems solved by technology

[0002] Emulsion polymerization is an important method for preparing monodisperse polystyrene microspheres. The prepared microspheres have high particle size uniformity and good shape integrity. However, due to the addition of emulsifiers during the reaction and the emulsifiers are difficult to remove after the reaction , so that it is subject to various restrictions in the application of many biomedical fields. In view of this, soap-free emulsion polymerization has developed rapidly

[0003] Soap-free emulsion polymerization refers to the emulsion polymerization process in which no emulsifier is mixed at all or only a small amount of emulsifier (its concentration is lower than the critical micelle concentration CMC) is added in the polymer polymerization process. Compared with conventional emulsion polymerization, soap-free emulsion polymerization The product has the following advantages: the product can be used directly; the cost of the product is reduced; the post-treatment process of the emulsifier is omitted; the surface of the latex particle is clean, thus avoiding the impact of the emulsifier on the optics, solvent resistance, film-forming property and surface of the product. Properties and other adverse effects, however, the amount of cross-linking agent used in cross-linked polystyrene microspheres produced by soap-free emulsion polymerization in China is far higher than that of monomers, and the cost is greatly increased

[0004] The patent application number is 200710164072.X discloses a preparation method of highly cross-linked monodisperse polymer microspheres, the amount of cross-linking agent is about 60% of the monomer amount, the amount of cross-linking agent increases, on the one hand increases The cost of preparing cross-linked polystyrene microspheres in industrialized production, on the other hand, the waste gas and waste liquid of cross-linking agent also increase the pollution to the atmosphere and water environment

In addition, domestic research on the control of carboxyl groups on the surface and interior of microspheres is relatively small. The patent application number 201010278715.5 discloses a method for preparing carboxylated polystyrene microspheres. Similarly, it is difficult to control the content of carboxyl groups on the inner and outer surfaces from a nanometer point of view. At present, solvent-resistant polystyrene microspheres are prepared for low crosslinking agent dosage, and the carboxyl content inside and outside the microspheres cannot be controlled.

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