High Tg and tough poly(butylene 2,5-thiophenedicarboxylate-co-1,4-cyclohexanedimethylene 2,5-thiophenedicarboxylate)s: Synthesis and characterization

The purpose of this study was to enhance the glass-transition temperature of poly(butylene 2,5-thiophenedicarboxylate) (PBTF). A series of poly(butylene- co -1,4-cyclohexanedimethylene 2,5-thiophenedicarboxylate)s (PBCTFs) were synthesized from 2,5-thiophenedicarboxylic acid, 1,4-cyclohexanedimethanol (CHDM), and 1,4-butanediol. CHDM can increase the chain rigidity and lead the β relaxation temperature shift to lower temperature. Consequently, PBCTFs showed not only the high glass-transition temperature, but also high elongations at break. PBTF was a crystalline polyester. However, differential scanning calorimetry and wide-angle X-ray diffraction results suggested PBCTFs were amorphous polyesters. Thermogravimetric analysis results indicated the thermal stability of copolyesters was gradually enhanced with increasing the CHDM content. When the CHDM content was 95 mol %, PBCTF95 exhibited high glass-transition temperature (69.2 °C), tensile strength (44.4 MPa), and elongation at break (205%). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48634.