Influence of microwave irradiation on thermal properties of PVA and PVA/graphene nanocomposites

This article discusses the effect of microwave irradiation on the thermal properties of poly(vinyl alcohol)/graphene nanocomposites, prepared using a solution casting technique. Samples were subjected to microwave radiation for 5, 10 and 15 min at a constant power of 200 watts. The crystallinity and thermal stability of the irradiated samples were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis. Reduction in crystallinity and thermal stability of PVA was observed with incorporation of graphene due to restricted dynamic movement of chains and synergistic instability, respectively. Microwave irradiation for 5 min improved the crystallinity and thermal stability of the nanocomposites. However, further irradiation caused a decrease in the crystallinity as well as in the thermal stability due to degradation. Moreover, the isothermal crystallization kinetics were studied by DSC. An increase in the crystallization rate was observed with graphene incorporation.