Preparation and Characterization of Poly(Trimethylene Terephthalate/Isophthalate/Carbonate)

ABSTRACT Due to the low notched impact strength, poly(trimethylene terephthalate) (PTT) with excellent toughness and good thermal properties have been attracted more attention. This study synthesized Poly(trimethylene terephthalate/isophthalate/carbonate) (PTTIC) copolymer with excellent notch impact strength from the green dimethyl carbonate (DMC) as the comonomer. The PTTIC copolymers with various DMC contents were synthesized via a two‐step melt polycondensation method. Their structure, thermal properties, crystallization behavior, mechanical properties, and rheological properties were systematically investigated. Mechanical property tests indicated that the introduction of DMC achieved the transformation of the material from “strong and brittle” to “resilient and durable”. PTTIC 30% achieved the optimization of toughness and its elongation at break and notched impact strength were greatly enhanced compared with pure PTTI. Rheological and dynamic mechanical analysis (DMA) showed that PTTIC 30% exhibited a unique viscoelastic balance behavior in the melt state, corresponding to its optimized impact resistance. This study verified the feasibility of copolymerization modification of PTTI using the green monomer DMC, and the introduction of DMC effectively improves the comprehensive toughness of the material. This work provides a valuable material basis and theoretical support for its application in high‐value‐added fields such as engineering plastics.