Chain-extension and thermal behaviors of poly(p-dioxanone) with toluene-2,4-diisocyanate

A method for enhancing the molecular weight of poly(p-dioxanone) (PPDO) has been provided in this investigation. Higher molecular weight biodegradable polymers have been prepared by chain-extending method from lower molecular weight PPDO using toluene-2,4-diisocyanate (TDI) as a chain extender. The prepolymers and the resulting polymers were characterized by 1H NMR, DSC, WAXD, and TG. The results show that TDI is an effective chain extender for PPDO. Comparing the chain-extended polymers with PPDO prepolymers, no obvious change in melting temperatures and crystal structures has been observed except that glass transition temperatures increase. The studies of the thermal-oxidative degradation of PPDO show that the thermal stability of chain-extended PPDO is higher than that of PPDO prepolymers.