28 Pages

Long Term in Vitro Enzymatic Biodegradation of Pellethane 2363-80A

A Mechanical Property Study
WithB.D. Angeline, A. Hiltner, J.M. Anderson

This chapter determines the effect of enzymic environments on the mechanical properties of Pellethane 80A. It considers papain and a plant thiol endopeptidase as the enzyme for the in vitro simulation of the in vivo environment. Rupture stresses among the enzyme treated samples did not differ significantly when compared to one another, suggesting that a single loading experiment was not sensitive enough to detect the varying levels of degradation. Single loading tensile tests did not reveal significant difference in mechanical properties following in vitro enzyme treatment, while cyclic stress fatigue tests and gel permeation chromatography (GPC) showed a decrease in properties following enzyme treatments. After completion of the treatments, the Pellethane 80A ribbons were removed and cleaned prior to mechanical testing and GPC analysis. In comparing the stress-strain curves for the enzyme treated samples, it becomes apparent that the curves are almost identical.