Chlorohydrin water-swellable rubber compatibilized by an amphiphilic graftcopolymer. II. Effects of PVA-g-PBA and CPA on water-swelling behaviors

A water-swellable rubber (WSR), compatibilized by the amphiphilic graft cop olymer, has been prepared by blending chlorohydrin rubber (CHR) with crossl inked polyacrylate (CPA), Poly(vinyl alcohol)-g-poly(butyl acrylate) (PVA-g -PBA), precipitated silica (PSA), and poly(ethylene glycol) (PEG). The WSR was characterized by scanning electron micrography (SEM). The dependence of the water-absorbing ratio by weight, the water-swelling ratio by volume, a nd the percentage loss by weight on PVA-g-PBA and crosslinked polyacrylate contents was investigated. The effect of PVA-g-PBA and crosslinked polyacry late contents on second water-swelling behaviors and long-term water-retent ion behaviors were also studied. (C) 1999 John Wiley & Sons, Inc.