Non-isothermal crystallization kinetics of biodegradable poly(butylene succinate-co-diethylene glycol succinate) copolymers

We have modified the properties of biodegradable poly(butylene succinate) (PBS) by incorporation of diethylene glycol to form poly(butylene succinate-co-diethylene glycol succinate) (P(BS-co-DEGS)) copolymers and investigated the fundamental properties and isothermal crystallization behaviors of P(BS-co-DEGS) in previous study. The non-isothermal crystallization is also important for the practical use since they are usually processed under non-isothermal conditions. Therefore, in the present paper we exclusively investigated the non-isothermal crystallization kinetics of P(BS-co-DEGS) and compared with that of neat PBS using differential scanning calorimeter. Three classical methods including Avrami, Ozawa, and Moʹs equations have been used to analyze the non-isothermal crystallization kinetics of neat PBS and P(BS-co-DEGS) copolymers. The results suggest that both Avrami and Moʹs methods are suitable while Ozawa method is not suitable to describe the non-isothermal crystallization of the polymers. The crystallization rate decreased gradually with increase in the content of DEGS while the crystallization mechanism almost kept unchanged. The non-isothermal crystallization activation energies were evaluated by Vyazovkin method and the results are in accordance with those obtained by other methods.