Synthesis and swelling behaviour of interpenetrating network polymers of poly(vinyl alcohol) and poly(acrylamide-co-potassium methacrylate)

A series of interpenetrating polymer networks (IPN) based on poly(vinyl alcohol) and poly(acrylamide-co-potassium methacrylate) were synthesized. The synthesis was effected by a semi-IPN method polymerizing an aqueous solution of acrylamide and potassium methacrylate using the APS/TMEDA initiating system with a cross-linker, in the presence of poly(vinyl alcohol). Four different cross-linkers were employed in the preparation of IPNs. The swelling behaviour of the IPNs was monitored as a function of acrylamide and potassium methacrylate ratios. The IPNs were synthesized by varying the cross-linker concentration and the experimental results showed that the cross-linker concentration is of great influence on the swelling behaviour. The network formation of IPNs cross-linked with various cross-linkers at two different concentrations was studied in detail by scanning electron microscopy (SEM). The IPNs being ionic, swelling is affected by the ionic strength as well as by the pH of the medium. Further the effect of simulated biological fluids on the swelling behaviour of PVA/poly(AAm-co-KMA) IPNs was also investigated.