A Synthetic Strategy for the Preparation of <scp>PETG</scp> With High‐Performance, Less By‐Products, and Good Comprehensive Properties

ABSTRACT Poly(ethylene terephthalate‐ co ‐1,4‐cyclohexanedimethylene terephthalate) (PETG) is a versatile engineering plastic with excellent properties and has been widely used in heat‐shrinkable films, sheets, and packaging. A series of PETG with various contents of 1,4‐cyclohexanedimethylene (CHDM) content was synthesized by transesterification and polycondensation. The PETG synthesized in this work has less DEG by‐product content and exhibits excellent combined properties. This is attributed to the fact that the transesterification process leads to the formation of methoxy terminal groups (–OCH 3 ) in PETG, which exhibit higher stability compared to hydroxyl terminal groups (–OH). In addition, the properties of PETG can be controlled at the macromolecular structure level by simply regulating the content of CHDM. The chemical structure, thermal properties, mechanical performance, rheological properties, and heat shrinkage performance of PETG were systematically studied. The results demonstrated that CHDM content significantly influenced crystallization behavior, glass transition temperature ( T g ), thermal stability, and rheological properties. This work offers a theoretical foundation for advancing high‐performance PETG and proposes novel synthesis strategies for applications. The results of this research support the promotion of the wide application of PETG materials in the packaging, medical, electronics, and automotive industries, especially in environmental protection and sustainable development, providing new development directions and solutions for the industry.