The swelling and collapse of hydrogen bonded polymer gels

The volume phase transitions in hydrogen bonded polymer gels are investigat ed. The elastic contribution is obtained by a modification of the Flory-Reh ner approach proposed previously, where the affine deformation assumption i s abandoned and instead the assumptions of the c* model of de Gennes are ad opted. The mixing term is modified to account for hydrogen bonding. The cal culations (both binary and ternary) clearly indicate the possibility of abr upt volume phase transition. Also the existence of LCST and UCST within an accessible temperature range is predicted for gels in mixed solvent systems involving hydrogen bonding. (C) 1999 Elsevier Science Ltd. All rights rese rved.