Stereoconformational Regulation of Nonplanar Six-Membered Rings: Preparation of Highly Reboundable Degradable Thermoplastic Polyester Elastomers

Using 1,4-cyclohexanedimethanol (CHDM) with different cis/trans configuration contents, succinic acid (SA), and ethylene glycol (EG) as monomers, a series of novel biodegradable thermoplastic polyester elastomers (PECSX-Y) were synthesized via a two-step esterification-polycondensation method. Differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) results show that increasing the content of trans six-membered rings enhances the overall crystallinity of the polymer while maintaining excellent thermal stability. Additionally, with the increase in trans six-membered ring content, the polymer transitions from an amorphous state to an elastomer. Mechanical property and cyclic recovery tests indicate that the elastomer achieves a modulus of up to 55 MPa, an elongation at break of 1400%, and a recovery ratio exceeding 80%. Degradation experiments demonstrate that PECSX-Y elastomers exhibit excellent degradability, and biological assays confirm their superior biocompatibility. Finally, by regulating the cis/trans configuration content of CHDM in PECSX-Y polymers, a series of thermoplastic elastomers with excellent properties were successfully prepared, providing new insights for the development of degradable thermoplastic elastomers.