Preparation and Characterization of Cross-Linked Poly(butylene succinate) by Multifunctional Toluene Diisocyanate–Trimethylolpropane Polyurethane Prepolymer

Cross-linked poly(butylene succinate) (PBS) was prepared by the reactions of the end hydroxyl groups of PBS with toluene diisocyanate and trimethylolpropane (TDI–TMP) polyurethane prepolymer at the processing temperature. The effects of varied TDI–TMP prepolymers on properties such as mechanical properties, thermal properties, dynamic mechanical properties, and crystal morphology were investigated. The results indicated that TDI–TMP prepolymer could cross-link PBS with high efficiency. The gel fraction of the cross-linked PBS increased with the content of TDI–TMP prepolymer, and the melt flow index of PBS decreased. Differential scanning calorimetry and dynamic mechanical analysis revealed that the crystallization temperature and glass transition temperature increased with the content of the TDI–TMP prepolymer, while the melting points and degree of relative crystallinity decreased. The cross-linked PBS also showed improved tensile properties, impact properties, thermal stability, and dynamic mechanical p...