Preparation And Property Of Thiol-acrylate Copolymer Microspheres Via Thiol-ene Reaction

Polymer microspheres have become a hot research topic in the field of materials and are widely used in biological materials, drug controlled release, intelligent separation, catalysis, oil exploitation and other fields due to their superior performance. The structure and size of microspheres have an important influence on their function. Inorganic/polymer nanoparticle composites combine the advantages of polymer and inorganic nanoparticles, showing the unique character of electricity, magnetism, light, sound, etc. many research scholars have concerned its application in medicine, biotechnology and other aspects. Thiol-ene reaction was widely used in functional materials, topology structure, life sciences, medicine, the surface modification and other fields, because of it is rapid, simple, pollution-free, and wide for application. In this paper, thiol-acrylate copolymer microspheres were synthesized via miniemulsion polymerization, and then microspheres were modified by different methods to improve the performance of composite microspheres. The main contents are as follows:In the first chapter, the research progresses, preparation and application of polymer microspheres in the recent years were summarized, especially for miniemulsion polymerization and inorganic/polymer nanoparticle composites. In short, miniemulsion polymerization is a relatively suitable method for nanocomposite microspheres preparation compared with other preparation methods. The research progresses of thiol-ene reaction were also introduced.In the second chapter, thiol-acrylate composite microspheres were synthesized via thiol-ene reaction in miniemulsion polymerization using TMMP and TMPTA as main materials. This study investigated the effects of emulsifier contents and monomer contents on the morphology of microspheres. The results showed that the microspheres synthesized by TMMP and TMPTA were regular spherical particles with uniform size. The higher the rate of emulsifier concentration and monomer concentration was, the smaller the microspheres were. When the emulsifier concentration was too high to protect the stability of the emulsion, the microspheres became bigger.In the third chapter, magnetic thiol-acrylate composite microspheres were synthesized via thiol-ene reaction in miniemulsion polymerization using TMMP, TMPTA and Fe3O4 nanoparticles (modified by OA or MPS) as main materials. This study investigated the effects of hydrophobic modifier type and monomer contents on the morphology of microspheres. The results showed that the microspheres synthesized by OA modified Fe3O4 of were around 200 nm with narrow size distribution. The amount of organic solvent, monomer and emulsifier have certain influence on the morphology of microspheres. The magnetic thiol-acrylate composite microspheres were coated by Fe3O4 particles at a rate of 51%, and had good magnetic responsibility.In the fourth chapter, Ag/thiol-acrylate composite microspheres were synthesized via thiol-ene reaction in miniemulsion polymerization using TMMP, TMPTA and Ag nanoparticles (modified by OA or MPS) as main materials. Another method was via in situ miniemulsion polymerization method using thiol-acrylate composite microspheres modified by carboxyl groups and nitrile groups (prepared by TMMP, TMPTA, AA and AN). This study investigated the effects of hydrophobic modifier type and different pH on the morphology of microspheres. The results showed that Ag/thiol-acrylate composite microspheres were regular spherical particles with uniform size. The size of Ag nanoparticles prepared by solution reduction method were 5-20 nm, the microspheres synthesized by OA modified Ag were better modified, and the microspheres were coated by Ag particles at a rate of 70%. The microspheres synthesized via in situ miniemulsion polymerization showed good catalytic properties.