Synthesis and characterization of copolymer hydrogels of chitosan, itaconic acid and N-isopropilacrylamide

Abstract

This paper deals with synthesis of copolymer hydrogels of N-isopropilacrylamide, itaconic acid and chitosan. During synthesis, pH of the reaction solution and temperature were varied. It was found that reaction at higher temperature, above lower critical solution temperature (LCST) value of N-isopropilacrylamide resulted in a formation of polymer rich domains or aggregates in the matrix of loosely tied network, which cause a higher degree of swelling. Moreover, reaction pH also affects the degree of swelling and contraction of hydrogels owing to the different ionization of the ionic groups presence in hydrogel. The values of diffusion exponent, n, indicate non-Fickian kinetics corresponding to diffusion and relaxation of polymer chains. These hydrogels could be classified as macroporous hydrogels. Hence, it is possible to synthetize hydrogels of desired functionality which allow their application in different fields.

Keywords

• N-isopropilacrylamide
• itaconic acid
• chitosan
• hydrogel
• swelling behaviour