Seawater-degradable poly(ethylene adipate-co-terephthalate) copolyester: Synthesis, properties, and degradation behavior

The application and promotion of biodegradable plastics are hindered by the imbalance between their mechanical and degradation performance imbalance, as well as high costs. Herein, a series of poly(ethylene adipate-co-terephthalate) (PEAT) copolyesters with excellent mechanical and degradation properties are synthesized by one-step melt polycondensation. The influence of the proportion of aliphatic groups in the molecular chain on the structure and properties, especially the degradation performance, of the copolyesters was studied. The molecular chain flexibility and degradability of PEAT increases with increasing of adipic acid content and decreasing of ET fragment length (L-ET). The comprehensive mechanical properties of PEAT60 can be comparable to traditional packaging material poly(butylene adipateco-terephthalate) (PBAT). The degradation performance of PEAT can be adjusted the molecular chain structure. PEAT with L-ET < 3 exhibit degradation performance, and PEAT with L-ET < 2.2 exhibit significant degradation acceleration. The excellent mechanical and degradable properties of PEAT copolyester make it expected to be used in degradable packaging and other fields to help solve plastic pollution, while its lower cost will aid in the promotion of degradable materials.