Poly(vinyl alcohol) (PVA) is a well-known biomedical polymer and is biocompatible. Methylmethacrylate and acrylic acid monomers were grafted onto PVA using a Ce(IV)-glucose redox system at three different temperatures (35, 45, and 55°C) under nitrogen atmosphere. More than 80% grafting could be achieved in the process. The grafted PVA was characterized through infrared spectra, thermal decomposition studies [thermogravimetric analysis (TGA) and decomposition thermal grafting (DTG)], differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The thermal stability and other properties of grafted PVA related to medical applications was found to be better than those of ungrafted PVA.

Replacement of a large proportion of -Ol;"O2 groups by -N3 groups in polymer chain ('azidation' of I PVN) enhanc~ reactivity, impact sensitivity and energetics, but reduced thennal stability of the products. The thennogravynetric analysis of PVN showed the onset of rapid decomposition at about 171 °C.jThe kinetic analysis of thennogravimetric results indicated the validity of random nucleation first-order reaction model.1A differential scanning calorimetry thennogram of PV AZ showed a peak at 183.9 °c and heat of d~omposition of 2732 JIg, which is lower than that for PVN. I. EXPERIM~NTAL DETAIUS2.