THERMORESPONSIBLE CRYOGELS BASED ON CROSS -LINKED POLY(N,N'-DIETHYLACRYLAMIDE)

Thermoresponsible poly(diethylacrylamide) macroisotropic gels and spon gy cellular heterophase hydrogels, which undergo reversible collapse u pon transition through the critical temperature, were synthesized by r adical copolymerization of N,N-diethylacrylamide and N,N'-methylenebis acrylamide in water at +20 degrees C and in a frozen system at -10 deg rees C, respectively. It was discovered that cryogels are characterize d by higher rates of thermally induced collapse. This is related to th e morphology of cryogels containing large amount of interconnected mac ropores, the thin walls of which are built up of highly concentrated g el. The osmotic and thermal properties of macroisotropic gels and anis otropic cryogels were studied. It was shown that, upon thermally induc ed conformation transition of the cross-linked chains of the polymer p hase of cryogels, the extent of hydration of a network drops to the po ssible limiting values.