Amphiphilic biodegradable graft copolymer, poly(vinyl alcohol)-graft-poly(p-dioxanone) (PVA-g-PPDO), was used to prepare a new biodegradable material by blending with poly(p-dioxanone) (PPDO). The in vitro degradation properties of the copolymer and blends with different contents of PVA-g-PPDO were studied in phosphate buffer at 37 degrees C. The degradation processes of the PVA-g-PPDO and its blends with the PPDO were monitored by weight loss, viscosimetry, water uptake, differential scanning calorimetry (DSC), and scanning electron microscopy. The results of inherent viscosity and weight loss reveal that the PVA-g-PPDO has a different in vitro degradation behavior from that of PPDO, and the introducing of copolymer into the blending system may enhance the degradability of PPDO when the contents of copolymer is higher than 5%. The change of the degree of crystallization (Dc) of copolymer and blends derived from the DSC also shows that the copolymer and blends have faster degradation rates than the neat PPDO during the testing period. A degradation mechanism of the blends was postulated based on the results of the weight retention, inherent viscosity measurement, and DSC.
Copyright 2006 Wiley Periodicals, Inc.