Effect of Self-nucleation Process on Isothermal Crystallization Behavior of Polybutylene Succinate

Self-seeding nucleation technique can improve the nucleation efficiency of semi-crystalline polymers, reduce the crystal particle size and improve polymer performance. The appropriate temperature scope of self-seeding nucleation, the effect of self-seeding nucleation on crystallization and subsequent melting behavior of bio-degradable poly(butylenes succinate) (PBS) were studied by DSC. The results show that the suitable temperatures of self-seeding nucleation for PBS are scope of 118 degrees C to 120 degrees C. The crystallization temperature of PBS increases obviously(about 20 degrees C) after suffered the self-seeding nucleation process. Isothermal crystallization in the range of temperature between 100 degrees C and 104 degrees C after melting for 5min at 118 degrees C were investigated, and the isothermal crystallization kinetics were analyzed by Avrami equation. The results suggest that the Avrami equation also can be applied to analysis the isothermal crystallization process of self-seeding nucleation PBS samples and the relative parameters including K and n were calculated. The n. value is high closing to 6, which results from the increasing of the growth point in crystal nucleus. The melting processes after isothermal crystallization were analyzed and the equivalent melting point of PBS was discussed by Hoffman-Weeks Equation. Multiple melting peaks can also be found on the heating DSC curves and there is no effect of the self-seeding nucleation process on equivalent melting point of PBS. Additionally, based on Arrhenius equation, the isothermal crystallization active energy of self-seeding nucleation PBS was calculated and the value was -286 kJ/mol.