Abstract: Poly(vinyl pivalate) exhibiting a high syndiotacticity and a high molecular weight is prepared through suspension polymerization of vinyl pivalate at low temperatures. Furthermore, poly(vinyl pivalate) microspheres with a high syndiotacticity is prepared for use as a precursor for PVA with a high molecular weight and a high syndiotacticity through suspension polymerization of vinyl pivalate at 20 to 70° C. with the use of azobisdimethylvaleronitrile as an initiator. In addition, poly(vinyl pivalate) is separated using a dispersing agent and a precipitating agent to thereby prepare poly(vinyl pivalate) microspheres with various sizes and a uniform size distribution. The poly(vinyl pivalate) microspheres are suspended in an aqueous alkali soloution such that only the surface thereof is saponified to PVA. In this way, embolic particles with a spherical shape are obtained to be useable as an embolic material for embolotherapy.

Abstract: Poly(vinyl pivalate) exhibiting a high syndiotacticity and a high molecular weight is prepared through suspension polymerization of vinyl pivalate at low temperatures. Furthermore, polyvinyl pivalate) microspheres with a high syndiotacticity is prepared for use as a precursor for PVA with a high molecular weight and a high syndiotacticity through suspension polymerization of vinyl pivalate at 20 to 70 ° C. with the use of azobisdimethylvaleronitrile as an initiator. In addition, polyvinyl pivalate) is separated using a dispersing agent and a predpitating agent to thereby prepare poly(vinyl pivalate) microspheres with various sizes and a uniform size distribution. The poly(vinyl pivalate) microspheres are suspended in an aqueous alkali solution such that only the surface thereof is saponified to PVA. In this way, embolic particles with a spherical shape are obtained to be useable as an embolic B material for embolotherapy.