Radiation induced crosslinking effect on semi-interpenetrating polymer networks of poly(vinyl alcohol)

Semi-IPNs with varying contents of polyI(vinyl alcohol) (PVA), poly acrylamide (PAM) and crosslinker N,N'-methylene bis acrylamide (MBA) were prepared by redox polymerization method. The structural and morphological properties were studied by Fourier transform infrared I(FTIR) spectroscopy, environmental scanning electron microscopy (ESEM) and X-ray diffraction (XRD) methods, respectively. It was found that the surface of the hydrogel is heterogeneous with separated domains. XRD result shows the semi-crystalline nature of the semi-IPNs. The prepared semi-IPNs of different compositions were subjected to gamma irradiation (2 to 250 kGy) and the radiation induced effects on their strength of the semi-IPNs were studied by measuring the surface microhardness using a Vickers microhardness tester. Significant changes were observed in the Vickers microhardness, which were correlated with molecular architecture of the prepared semi-IPNs.