Synthesis and characterization of polyvinyl alcohol based semi interpenetrating polymeric networks

Polymeric networks in the form of hydrogels offer possibilities to achieve desirable combination of properties that are generally not available in a single polymeric material. With these objectives, the present work focus on the synthesis of polyvinyl alcohol (PVA) based novel semi-IPNs of varying compositions by redox polymerization method using N,N'-methylene bisacrylamide (MBA) as the crosslinker and acrylonitrile as the monomer. The prepared semi-IPNs have been examined for structural confirmation, by FTIR analysis. Crystalline features of the semi-IPNs were studied by XRD technique which revealed that crystallinity in the membrane was mainly due to PVA. The IPNs of various compositions have also been examined for their water sorption behavior and network parameters like average molecular weight between crosslinks (M-c) and crosslink density were calculated from water imbibition measurements. The kinetics and mechanism of water sorption process were studied and related kinetic parameters were evaluated. The DSC analysis of the prepared semi-IPNs was also performed and it was found that the gels showed well-defined thermal behavior.