Engineering of polybutylene succinate with long-chain branching toward high foamability and degradation

Long-chain branched (LCB) polybutylene succinate (PBS) was successfully prepared by the reaction of linear PBS with epoxy-based multifunctional oligomer and triglycidyl isocyanurate. The melt foamability of PBS with different LCB degree were evaluated by the batch foaming with supercritical CO2. The existence of LCB structures led to the increased complex viscosity and storage modulus, reduced loss factor and enhanced strain hardening behavior, leading to the enhancement of the foamability. It is discovered that the LCB-PBS had a broadened foaming window of 30 degrees C, and can obtained the maximum expansion ratio of 42.5 while that of linear PBS was only 14.5. Moreover, the cell morphology and expansion ratio of foamed sample can be easily adjusted by changing the LCB degree. Importantly, the PBS sample can still maintain good biodegradability with the appropriate modification. The degradability-foamability relationship of PBS was thoroughly discussed, which also can afford shed light upon the large-scale preparation of the biodegradable and foamable polyester. (C) 2021 Elsevier Ltd. All rights reserved.