Synthesis and transport properties of poly(vinyl alcohol) acrylonitrile/2-hydroxyethyl methacrylate membranes—I. Synthesis of poly(vinyl alcohol) acrylonitrile 2-hydroxyethyl methacrylate graft copolymer

Abstract

The graft copolymerization of acrylonitrile and hydroxyethyl methacrylate monomers onto poly(vinyl alcohol) backbone using the ceric ion technique was investigated in detail and a high percentage grafting of the monomers onto the backbone was obtained. Another backbone which was investigated was a blend of poly(vinyl alcohol) and polyacrylic acid (PVA-PA). The grafting onto the poly(vinyl alcohol) was found to depend on the concentration of the ceric ion and its acidity and the poly(vinyl alcohol) content. Grafting was observed to proceed very smoothly onto the poly(vinyl alcohol) but was much slower in the poly(vinyl alcohol)/poly(acrylic acid) system. The graft copolymerization was interpreted in terms of an emulsion polymerization in the case of the poly(vinyl alcohol) system. However, grafting did not proceed very readily in the poly(vinyl alcohol)/poly(acrylic acid) blend system, explained by a coagulation which caused the system to react more slowly.