Biodegradable Polyester-Based Vitrimers Exhibiting Transesterification-Induced Topography Isomerization under Recycling

Abstract

In this work, biodegradable and polyester-based vitrimers possessing dynamic ester bonds are prepared by chemically cross-linking −OH-containing poly(glycerol sebacate) (PGS) with the formation of interchain ester bonds. In enzymatic biodegradation tests, the vitrimers demonstrate high extents of degradation (of about 85−90 wt %) after 60 days at 37 °C. The excess hydroxyl groups in the vitrimers bring a catalytic effect to transesterification. The catalyst-free vitrimers exhibit a stress relaxation time of 390 s at 190 °C, an activation energy of 45.0 kJ mol −1 , a glass transition temperature of 8.0 °C, and a topology freezing transition temperature of 48.7 °C. Possessing dynamic ester bonds at both PGS main chains and the side cross-linking sites, the vitrimers exhibit topography isomerization and changes in their mechanical properties under thermally recycling processes. The biodegradable PGS has been demonstrated as an effective precursor for preparation of the corresponding vitrimers. Moreover, the mechanical changes and topography isomerization of the vitrimers in the recycling processes could be of interest for further studies and potential applications.