Synthesis and Characterization of pH Responsive Polyvinyl alcohol Hydrogels with Chitosan and Polyacrylonitril

By : Fawzi Habeeb Jabrail, Ahmad Zaki Ahmad, Kailash Chandra Gupta

Page No: 539-553

Abstract
Physically and chemically cross-linked hydrogels were prepared using polyvinyl alcohol (PVA) in combination with chitosan (CH), pectin (PE), alginate (AL) and polyacrylonitrile (PAN) and characterized for their physical properties. The physically cross-linked hydrogels were prepared by applying freezing and thawing technique and their responses were compared with hydrogels cross-linked with glutaraldehyde (25%). The structures of hydrogels were characterized by recording their IR spectra and mechanical strengths were evaluated as young’s modulus and elongation at break. The PVA hydrogels with different polymers have shown significant variations in their mechanical properties and found to be responsive toward solution pH. The water sorption capacity and degree of swelling (DS%) of hydrogels are found to be dependant on solution pH and temperature. Thermal properties of hydrogels were analyzed using differential scanning calorimetric (DSC), and thermogravimetric (TGA) analysis. The polymer blended PVA hydrogels are found to be thermally stable as compared to pristine PVA hydrogels. The glass transition temperature (Tg) of polymer blended hydrogels is found to be significantly higher in comparison to pristine PVA hydrogels. The scanning electron micrographs have indicated homogeneous morphologies for polymer blended PVA hydrogels and surface porosity on cross-linking is considered responsible for the uptake of water and other biological fluids.

Authors :
Fawzi Habeeb Jabrail and Ahmad Zaki Ahmad : Department of Chemistry, College of Science, University of Mosul, Mosul-Iraq
Kailash Chandra Gupta : Department of Chemistry, Indian Institute of Technology, Roorkee-247 667, India.