In this paper

narrow dispersing core-shell microparticles was synthesized by composite emulsion polymerization

with particle size 70-160nm. The core/shell structure of microgel was observed and determined by TEM clearly. Main factors influencing microgel's structure were discussed by HPTLC densitometry

TEM

GPC and viscosity method etc. . Experimental results showed that when bisvinyl-A is 1-4%(wt. ) of monomer I

first-stage polymerizing time is 2h

the core-shell microparticles will be obtained which having apparent viscosity value 140-165ml/g and containing 8-16% linear PS. The shell was mainly composed of branching chain linking to core.