Unsaturated poly (butylene adipate-co-butylene itaconate) (PBABI) copolyesters were synthesized through melt polymerization composed of 1,4-butanediol (BDO), adipic acid (AA), itaconic acid (IA) and 1,2,4,5-benzenetetracarboxylic acid (BTCA) as a cross-linking modifier. The melting point, crystallization and glass transition temperature of the PBABI copolyesters were detected around 29.8-49 °C, 7.2-29 °C and -51.1 and -58.1 °C, respectively. Young's modulus can be modified via partial cross-linking by BTCA in the presence of IA, ranging between 32.19-168.45 MPa. Non-isothermal crystallization kinetics were carried out to explore the crystallization behavior, revealing the highest crystallization rate was placed in the BA/BI = 90/10 at a given molecular weight. Furthermore, the thermal, mechanical properties, and crystallization rate of PBABI copolyesters can be tuned through the adjustment of BTCA and IA concentrations.
Keywords: 1,2,4,5-benzenetetracarboxylic acid; copolyester; partially cross-linking; poly(butylene adipate); poly(butylene itaconate); thermoplastic.