The novel octafunctional crosslinker glyoxal bis(diallylacetal) (GLY) was e
mployed in the synthesis of thermosensitive hydrogels of (N-isopropylacryla
mide -co-acrylic ac id). The resultant che mic ally crosslinked networks sh
ow levels of swellability in water significantly higher than those previous
ly reported for such copolymers crosslinked by N,N'-methylene bisacrylamide
(BIS) whilst retaining the ability to deswell at temperatures above the lo
wer critical temperature (T-c). Additionally, the replacement of BIS by GLY
yielded a decrease in the T-c of the hydrogels, indicating that incorporat
ion of GLY into the polymer network increases the hydrophobicity of the net
work; this is consistent with the structure of GLY and its sparing solubili
ty in water. (C) 2000 Elsevier Science Ltd. All rights reserved.