Characterization of crosslinked, macroporous, monosized polymer particles

Macroporous, monosized poly(meta-divinylbenzene) and poly(para-divinyl-benz ene) beads have been prepared by the two-step activated swelling metllod wi th toluene or 2-ethylhexanoic acid as pore-forming agents. The type of divi nylbenzene isomer as well as the type of porogen has a large effect on both physical and chemical properties of the monodisperse beads. Large pores ar e obtained with 2-ethylhexanoic acid as porogen while beads prepared in the presence of toluene consist of only small pores and exhibit a shrinking be havior upon drying. The beads have considerable amounts of residual vinyl g roups at the end of polymerization, as determined by bromination and Fourie r transform IR analysis. The morphology and texture of the particles have b een investigated by scanning electron microscopy and atomic force microscop y. (C) 2000 John Wiley & Sons, Inc.