Bio-based functional monomer-based high thermal and mechanical performance TPEE

• The incorporation of ISB into TPEE significantly enhanced their thermal stability and mechanical properties. • ISB effects on polymer crystallization were studied via isothermal and non-isothermal kinetics • LCA evaluated ISB in enhancing polymer sustainability and reducing environmental impact. Thermoplastic polyester elastomers (TPEEs) are widely used in daily life due to their excellent elasticity and processability. However, to broaden their application scope, there is a growing need to enhance their fundamental properties such as heat resistance and mechanical strength. This study aims to address this challenge by synthesizing novel bio-based TPEEs through melt polycondensation, using terephthalic acid (PTA), 1,4-butanediol (BDO), and isosorbide (ISB) as hard segment monomers, and poly(tetramethylene glycol) (PTMG) as the soft segment. This study strategically incorporates ISB into the hard segment architecture. Its unique molecular structure significantly alters the chain mobility and packing behavior of the copolymer, effectively regulating the material’s thermal properties, mechanical performance, and crystallization characteristics. The synthesized TPEEs exhibit a melting temperature range of 185–220 °C, tensile strength of 22–30 MPa, and tensile modulus of 38–95 MPa. A systematic investigation of the crystallization behavior of PBT-ISB-PTMG under isothermal and non-isothermal conditions was conducted. Experimental results indicate that the enhanced chain rigidity and steric hindrance introduced by ISB disrupt the ordered alignment of molecular chains, leading to a reduced crystallization rate and decreased overall crystallinity. In addition to performance improvements, the study emphasizes environmental sustainability. A preliminary life cycle assessment (LCA) shows that replacing 50% of conventional PBT hard segments with ISB reduces carbon dioxide emissions by approximately 19.5%. These findings demonstrate the potential of PBT-ISB-PTMG elastomers not only for high-performance applications but also as eco-friendly alternatives supporting sustainable development.