Controlled Particle Size, Monodisperse Polymer Copolymer Microspheres Research

Polymer microspheres have been used in coatings, adhesives, plastic additives, biochemistry and electronical information. The study on polymer microspheres is divided into two classes: preparation and application. There are a few methods to prepare polymer microspheres. After valuing all kinds of preparation's methods, this paper was aimed at preparing the micro-size and submicron monodisperse poly(styrene-methylmethacrylate) (P(St-MMA)) particles by dispersion polymerization and emulsifier-free emulsion polymerization respectively. Firstly, some pretty polymerization system was chosen, and then, the influences of polymerization parameters on particle size and size distribution were investigated to find out the reasonable polymerization way of P(St-MMA) monodisperse particles.A series of experiments were conducted to get the effects of polymerization parameters on particle size and size distribution. Then the products were characterized by FTIR, SEM, TEM and DLS. The results show that: (1)In the reaction system of dispersion polymerization, the size of microspheres decreases with increasing amount of stabilizer and decreasing initiator concentration; Initial monomer concentration could increase particle size and broaden the size distribution, While introducing the monomer in a lump administers to obtaining monodisperse copolymer microspheres. (2)In the reaction system of emulsifier-free emulsion polymerization, With increasing concentration of methylmethacrylate or initiator, the particle size dropped and the polydispersity index enlarged.In conclusion, The optimized recipes for preparing 0.44μm, 0.46μm, 1.74μm, 2.01μm P(St-MMA) monodisperse particles have been gotten.