Highly efficient cross-linking of poly(trimethylene carbonate) via bis(trimethylene carbonate) or bis(ε-caprolactone)

Abstract

To improve the form-stability and lower the degradation rate of poly(trimethylene carbonate) (PTMC) in biomedical fields, the cross-linked PTMC networks (PTMC-Ns) with controllable properties were prepared via chemical cross-linking. We report higher gel percentage and lower swelling degree as well as enhanced thermal and mechanical properties of the PTMC-Ns by increasing the initial molecular weight and by increasing the cross-linker amount. The PTMC-Ns cross-linked by bis(trimethylene carbonate) (BTB) had similar properties to that of counterparts cross-linked by 2, 2-bis(ε-CL-4-yl)-propane (BCP), indicating that BTB can be used interchangeably with BCP. Through in vitro enzymatic degradation, the 0.05 mol% BTB cross-linked PTMC with an initial molecular weight of 256 kDa displayed a mass loss of 34% and an erosion rate of 6.94 μm/d after 12 weeks—this was markedly slower than that of the uncross-linked samples. The PTMC-Ns have potential as biomedical implants because of their better form-stability and lower erosion rate than that of PTMC.