Preparation and pH responsive behavior of poly(vinyl alcohol)chitosan-poly(acrylic acid) full-IPN hydrogels

A full-interpenetrating polymer network (Full-IPN) hydrogel based on poly(vinyl alcohol)/chitosan/poly(acrylic acid) by the simultaneous-IPN method was synthesized and characterized by FT-IR and scanning electron microscopy. By varying the composition, different gels with different swelling dynamics, pH behavior and shrinking behavior of the gels were obtained. All the hydrogels swelled and reached equilibrium within five hours, indicating that the hydrogels have fast swelling properties and a relatively high swelling ratio (SR). Increasing the hydrophilic PAA in the full-IPN hydrogels increased the SR. The introduction of PVA and CTS to the full-IPN enhanced the hydrogel's biocompatibility. The poly(vinyl alcohol)/chitosan/poly(acrylic acid) full-IPN hydrogels exhibited a swelling change in response to pH of the swelling medium, and could be useful a potential modulation systems in biomedical fields.