Nonswellable and swellable ethylene glycol dimethacrylate-acrylic acid copolymer microspheres

Abstract

In this study, nonswellable and swellable poly(ethylene glycol dimethacrylate/acrylic acid) copolymer microspheres, in the size range of 50–150 μm, were produced by conventional and modified suspension copolymerizations of the respective monomers, i.e., ethyleneglycol dimethacrylate (EGDMA) and acrylic acid (AA) in aqueous media. Poly(vinyl alcohol) and benzoyl peroxide were used as the stabilizer and the initiator. The diluent, i.e., toluene was included in the polymerization recipe of the modified suspension polymerization. The microspheres were characterized by optical microscopy, FTIR, and FTIR-DRS, and potentiometric titrations. Highly crosslinked, transparent, and nonswellable poly(EGDMA/AA) microspheres were obtained with the conventional suspension polymerization procedure. The modified suspension polymerization provided swellable, opaque, and crosslinked copolymer microspheres. Acrylic acid incorporation into the copolymeric microspheres were significantly higher in the modified procedure, relative to the conventional procedure. © 1996 John Wiley & Sons, Inc.