Enhancement of mechanical and thermal properties of PBSeT copolyester by synthesizing AB-type PBSeT-PLA macromolecules

Material scientists have investigated biodegradable materials with excellent mechanical properties and high melting points. In this study, an AB-type poly(butanediol sebacate-butane diol terephthalate)-polylactic acid (PBSeT-PLA) macromolecule was synthesized using the esterification-polycondensation-esterification method, with hexamethylene diisocyanate (HDI) unit serving as a chain extender. Analysis using FTIR, ¹H NMR, and XRD confirmed the synthesis of PBSeT-PLA rather than a mere blend. Differential scanning calorimetry (DSC), thermogravimetric analysis (TG), and Vicat softening temperature (VST) tests revealed that the melting and Vicat softening points of PBSeT-PLA were increased by 30 °C and 15 °C, respectively, compared to PBSeT. Furthermore, the tensile strength, puncture load, and tearing strength of P2 (PBSeT-PLA, with an NCO to OH ratio of 1.5) were enhanced by 32.8%, 38.5%, and 71.8%, respectively, compared to PBSeT. Enzymatic degradation experiments demonstrated that the synthesized materials are biodegradable, with degradation initiating at the material surface. Overall, the thermal and mechanical property improvements suggest that PBSeT-PLA holds promise for applications in agricultural films and packaging materials.