Relationships Between Sequential Structure and Physicochemistry Performance for CO 2 ‐Derived Semi‐Aromatic Poly(Carbonate‐Ester) Terpolymers

ABSTRACT Poly(propylene carbonate) (PPC), the alternating copolymers of carbon dioxide (CO 2 ) and propylene oxide (PO), is a commercialized biodegradable plastic with excellent transparency, low cost, and full biodegradability. Moreover, its molecular chains are flexible and highly dense, giving it outstanding gas barrier properties and promising applications in areas such as food and pharmaceutical packaging. In order to further enhance the application potential of PPC in terms of thermal stability and gas barrier performance, terpolymerization of CO 2 /PO/phthalic anhydride (PA) is conducted via both one‐pot/two‐step and one‐pot/one‐step methods using a metal‐free catalytic system. Polycarbonate‐polyester terpolymers (PPC‐P) with different sequence structures but similar molecular weight and approximately 43% polyester content were synthesized by adjusting reaction conditions. The thermal degradation behavior of PPC‐P was investigated using TG/IR and Py‐GC/MS techniques. Furthermore, a comprehensive study was conducted to examine the influence of sequence structures on the thermal stability, mechanical properties, oxygen/water barrier performance, and alcoholysis behavior of PPC‐P materials. The results demonstrate that the sequence structure of polymers influences its thermal stability, gas barrier, and alcoholysis behavior. This work not only elucidates the relationship between polymer sequential structure and performance but also provides the foundation for the development of biodegradable materials in food applications.