Non-isothermal Crystallization Behaviors of Poly(p-dioxanone) and Poly(p-dioxanone)-b-poly(butylene succinate) Multiblock Copolymer from Amorphous State

A novel alternating multiblock copolymer poly(p-dioxanone)-b-poly(butylene succinate) (PPDOBS) was prepared through a two-step process including the initial ring-opening polymerization of p-dioxanone (PDO) initiated by poly(butylene succinate)-diol and the following chain extension, using hexamethylene diisocyanate (HDI) as a chain extender. The resulting PPDOBS was characterized by hydrogen nuclear magnetic resonance spectroscopy ((HNMR)-H-1), wide angle X-ray diffraction (WAXD), and differential scanning calorimeter (DSC). The WAXD analysis showed that the introduction of PBS segments did not change the crystal structure of PPDO. The heating scans of DSC curves showed that the cold crystallization temperature was decreased after the introduction of PBS segments, which indicated that the ability of PPDO to crystallize was improved. The non-isothermal crystallization kinetics of PPDO and PPDOBS were evaluated by means of Avrami, Ozawa, and Mo methods. It was found that the Ozawa method was not suitable to describe the crystallization kinetics for both PPDO and PPDOBS. The results of Avrami and Mo methods showed that crystallization rate of PPDO were enhanced by introduction of PBS segments. In addition, the activation energies for non-isothermal crystallization calculated using the Kissinger method for PPDO and PPDOBS were 46 kJ/mol and 38 kJ/mol, respectively, indicating the crystallization ability of PPDO was improved after the introduction of PBS segments.