Degradation behaviors of polyesterurethane network in oxidative environments

PMSE 328

Yakai Feng Sr., yakaifeng@hotmail.com, Polymer Science Department, Tianjin University, School of Chemical Engineering and Technology, Weijing Road 92, Tianjin, 300072, China
In this study H2O2/CoCl2 system was used as an oxidative environment to investigate the in vitro degradation behavior of a crosslinked polyesterurethane network. Weight loss, water absorption, mechanical properties, swelling degree and gel content were determined as a function of degradation time. The results showed that the H2O2/CoCl2 system could effectively accelerate the degradation of the polyurethanes. The weight loss process could be approximately divided into three major phases: the weight decreased slowly during an induction phase (1), which was followed by a phase characterized by accelerated weight loss (2), and finally by a phase showing slowly linear weight loss until complete erosion (3). The glass transition temperature of degraded polyesterurethane networks decreased significantly with increasing degradation time. From these results the H2O2/CoCl2 system can be used as an oxidative condition to evaluate the in vitro degradability of polyesterurethane.