The poly (acrylonitrile-co-vinylidene chloride-co-divinylbenzene) beads with macroporous morphology were synthesized by suspension polymerization. The use of dichloroethane as a solvating diluent resulted in copolymer beads having highly porous structures. These have been reacted with hydroxylamine in methanol, which generates amidoxime groups. The precursory resins were readily functionalized within 0.5-1 h. A detailed analysis is made of the pore structure of resins in the anhydrous state including pore size distribution and specific surface area. (C) 1994 John Wiley & Sons, Inc.