Modifying Poly(caprolactone) Degradation through C–H Functionalization

There is a growing need for degradable polymers for applications in sustainable plastics and medical implants. To enhance the utility of degradable polymers, both better understanding of the factors that influence their degradation and new tools to modulate degradation are needed. We report the C–H xanthylation of poly­(caprolactone), a biodegradable polyester, which results in changes in materials properties even at small incorporations. Despite the functionalized materials exhibiting a decrease in crystallinity and hydrophobicity, xanthylated poly­(caprolactone) degrades more slowly than its unfunctionalized counterpart. To understand this rate difference, kinetic studies with a small-molecule surrogate were performed and demonstrated that functionalization adjacent to the hydrolyzable ester functional group led to slower degradation. This study illustrates how the interplay between molecular and materials characteristics can impact degradation.