Effect of polycarbodiimide on the thermal stability and crystallization of poly(p-dioxanone)

A kind of polycarbodiimide (PCD) as a thermal stabilizer was added into poly(p-dixoanone) (PPDO). The effect of PCD on the thermal stability and crystallization of PPDO was investigated by using non-isothermal thermalgravimetry (TG), differential scanning calorimetry (DSC), polarized optical microscopy (POM) and wide angle X-ray diffractometry (WAXD). It has been shown that the addition of PCD can enhance significantly the thermal stability of PPDO. The thermal decomposition temperature of PPDO increases with the increase of the amount of PCD added. The activation energies for non-isothermal thermal degradation estimated by Kissinger method are 160 and 106 kJ mol⁻¹ for PPDO added with 5 wt% PCD and neat PPDO respectively. The results obtained from DSC and POM indicate that PCD plays a role of nucleating agent in the process of crystallization of PPDO. WAXD analyses reveal that the addition of PCD has no effect on the crystal structure of PPDO.