Modification of biodegradable poly(butylene carbonate) with 1,4-cyclohexanedimethylene to enhance the thermal and mechanical properties

Aiming to improve thermal stability of poly(butylene carbonate) (PBC), a series of poly(butylene-co-1,4-cyclohexanedimethylene carbonate) (PBCCs) random copolycarbonates with weight-average molecular weights (Mw) ranging from 1,09,000 to 1,74,000 g mol−1 and yield of 82.4to 88.4% were synthesized from Diphenyl carbonate (DPC), 1,4-butanediol (BD) and trans-1,4-cyclohexanedimethanol (CHDM) by a two-step melt polycondensation method. The structures and properties were characterized by 1H NMR, 13C NMR, FT-IR, GPC, WAXD, DSC, TGA, mechanical testing as well as enzymatic degradation. The results manifested that the triad components were existed in the copolymers with a random sequential structure, and incorporation of cyclohexanedimethylene carbonate (CC) units into PBC could prominently impact the thermal transition behavior, crystallinity as well as thermal stability of PBCCs in a degree. In addition, Tg of PBCCs monotonously increased with the increasing CHDM content. WAXD results indicated that the CHDM introduction could obviously change the crystal structure and crystallinity of the copolymers. The thermal stability of PBCCs also expressed to be enhanced during the process of increasing CC unit content. Furthermore, the mechanical properties and biodegradability of copolymers can be easily adjusted by regulating the feed composition.