EFFECT OF DILUENTS ON THE POROUS STRUCTURE OF CROSS-LINKED POLY(METHYL METHACRYLATE) BEADS

Copolymer beads based on methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDM) were prepared by suspension polymerization tech nique. Two different solvents, namely toluene and cyclohexane, were us ed as the diluents in the polymerization system. It was found that tol uene produces pores of radii 2 to 10 nm corresponding to the interstic es between the nuclei. In the case of cyclohexane as the diluent, form ation of large pores with a broad size distribution from 10 to 1000 nm were observed. These sizes correspond to the spaces between the micro spheres and the aggregates forming the copolymer beads. The results in dicate that, as in porous styrene - divinylbenzene copolymers, the sol vating power of the diluent present during the network formation is ma inly responsible for the structural characteristics of porous MMA/EGDM copolymer beads.