Effects of experimental variables on the synthesis of porous matrices

Macroporous beads, poly(ethylene glycol dimethacrylate-co-acrylic acid) [po ly(EGDMA-co-AAc)], and poly(ethylene glycol dimethacrylate-co-hydroxyethyl methacrylate) [poly(EGDMA-co-HEMA)] were prepared by the suspension polymer ization technique in the presence of a porogen agent. Different experimenta l conditions such as amount of initiator, porogen type, and temperature wer e studied to optimize the polymerization systems. These hydrophilic copolym ers were characterized by IR spectroscopy, scanning electron microscopy, sp ecific surface area, and swelling in water. A new parameter, H, defined as the ratio between the equilibrium weight swelling ratio (q(w)) and equilibr ium volume swelling ratio (q(nu)), allowed to select the reaction condition s from which matrices with high capacity of water sorption and low stretchi ng degree were reached. (C) 2000 John Wiley & Sons, Inc.