CORE-SHELL FUNCTIONAL MICROSPHERES BY DISPERSION POLYMERIZATION .2. SYNTHESIS AND CHARACTERIZATION

Polystyrene microspheres ranging in diameter from 3 to 10 mu m were pr epared in alcoholic media by dispersion polymerization of styrene in t he presence of a methacrylic acid/ethyl acrylate 1:1 statistical copol ymer (Eudragit) as the stabilizer precursor. The effects of the initia l Eudragit and free radical initiator concentrations on the microspher e dimensions, the microsphere size distribution and surface functional ity were investigated. The particle dimensions were found to increase with increasing initiator concentration and decrease with increasing s teric stabilizer precursor concentration. The percentage Eudragit in t he microspheres was found to increase with the stabilizer precursor co ncentration and decrease with the initiator concentration. The resulti ng double-shell microspheres, with specific surface functionalities, a re promising as tailor-made supports for biocatalysts.