The grafting of acrylamide onto poly(ε‐caprolactone) and poly(1,5‐dioxepan‐2‐one) using electron beam preirradiation. III. The grafting and in vitro degradation of chemically crosslinked poly(1,5‐dioxepan‐2‐one)

Acrylamide was graft polymerized onto the surface of a chemically crosslinked and amorphous biodegradable polyester, poly(1,5‐dioxepan‐2‐one). Electron beam irradiation at a dose of 5 Mrad was used to generate the initiating species in the polyester. The degradation behavior in vitro at pH 7.4 and 37°C in a phosphate buffer solution was studied for untreated, irradiated, and acrylamide‐grafted polymer. Differences in weight loss performance were observed between virgin and treated polymers. The acrylamide‐grafted poly(1,5‐dioxepan‐2‐one) was totally degraded after 43 weeks as compared to 48 weeks for the irradiated and 55 weeks for the virgin polymer. On the other hand, the treated polymers showed a higher resistance to degradation in terms of weight loss during the intermediate part of the degradation, i.e., between about 5 and 35 weeks. After this period, the irradiated and particularly the acrylamide grafted poly(1,5‐dioxepan‐2‐one) degraded much more rapidly than the virgin polymer. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1659–1663, 1999