Development of Biodegradable Poly(ester-carbonate)s with Tailored Rigid-Flexible Structures for High-Performance Packaging

Escalating environmental concerns over nondegradable plastics have driven the development of biodegradable copolyesters for sustainable packaging. This study introduces a novel series of rigid-flexible poly(ester-carbonate)s (PBCCTs) synthesized by incorporating 1,4-butanediol (BDO) and trimethyl citrate (TMC) into a rigid framework. The synergistic integration of flexible BDO units, rigid cyclohexyl rings, and in situ three-armed branched architecture enhances chain entanglement, overcoming the mechanical-biodegradability trade-off in commercial copolyesters like PBAT. PBCCTs offer tunable high-performance with superior optical, mechanical, and degradation properties: tensile strengths of 20.1-35.3 MPa, elongation at break of 206.0-500.0%, and tear strength up to 104 N mm^-1. The preferential scission of aliphatic carbonate units at targeted degradation sites imparts markedly enhanced degradability to the copolyester, with PBCCT₇₀ showing a mass loss of 64.49 wt %. Hemolysis and cytotoxicity assays confirm excellent biocompatibility, positioning PBCCTs as promising materials for robust, sustainable packaging.