Thermal properties and non-isothermal cry- stallization behavior of biodegradable poly(p-dioxanone)/poly(vinyl alcohol) blends

Blends of two biodegradable semicrystalline polymers, poly(p-dioxanone) (PPDO) and poly(vinyl alcohol) (PVA) were prepared with different compositions. The thermal stability, phase morphology and thermal behavior of the blends were studied by using thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). From the TGA data, it can be seen that the addition of PVA improves the thermal stability of PPDO. DSC analysis showed that the glass transition temperature (Tg) and the melting temperature (Tm) of PPDO in the blends were nearly constant and equal to the values for neat PPDO, thus suggesting that PPDO and PVA are immiscible. It was found from the SEM images that the blends were phase-separated, which was consistent with the DSC results. Additionally, non-isothermal crystallization under controlled cooling rates was explored, and the Ozawa theory was employed to describe the non-isothermal crystallization kinetics. (c) 2006 Society of Chemical Industry.