Synthesis of full bio‐based, fast degradable, and high strength copolyesters: Poly(butylene succinate‐sebacicate‐salicylicate‐malicate)

The presence of petroleum‐based monomers in the backbone of poly(butylene succinate‐co‐adipate) (PBSA) restricts its application in light of increasingly stringent environmental regulations. In this study, a novel full bio‐based biodegradable random copolymer poly(butylene succinate‐sebacicate‐salicylicate‐malicate) (PBSSeSa‐c‐M) was designed and synthesized. The comprehensive study encompassed the structural alterations, properties, and degradation resulting from the inclusion of salicylicate sebacicate and malicate units. The incorporation of salicylic acid effectively enhanced the tensile modulus of the copolymer, due to the effect of rigid benzene ring. Meanwhile, the addition of sebacic acid regulated the degradation rate. The introduction of malic acid significantly improved the rheological properties, endowing the copolymer with exceptional processability. The obtained high molecular weight PBSSeSa‐c‐M exhibited outstanding film‐blowing processability with an intrinsic viscosity of 1.58 dL/g and melt flow rate of 7.34 g/10 min. The tensile modulus reaches 235.43 MPa that is comparable to commercial PBSA. Besides, the degradation of PBSSeSa‐c‐M reaches 18.92% over 4 weeks, far higher than that of PBSA. In conclusion, this work provides a design and synthesis for a new kind of biodegradable copolyester that satisfies the requirement of rapid degradation in single‐use plastics.