Synthesis and properties of biobased polycarbonate based on isosorbitol

In this study, iso-sorbitol type polycarbonate (PIC) was synthesized with isosorbide (ISB) and diphenyl carbonate (DPC) as reactive monomers. The flexible co-monomers 1,4-butanediol (BDO) and 1,4-cyclohexane dimethanol (CHDM) were introduced to improve its property. Then, two iso-sorbitol type polycarbonate copolymers were obtained: Isosorbitol type polycarbonate copolymer (PIBC) containing 1,4-butanediol (BDO) and isosorbitol type polycarbonate copolymer (PICC) containing 1,4-cyclohexane dimethanol (CHDM). The results of 1 H-NMR and FT-IR demonstrated that the structures of PC, PIC, PIBC, and PICC synthesized by the experiment were consistent with the theoretical structures. The results of the characteristic viscosity test suggested that the copolymer with high relative molecular weight was successfully prepared. The results of DSC and TGA revealed that the introduction of a flexible copolymer increased the relative molecular weight of the copolymer, decreased the glass transition temperature, and exerted little effect on the thermal stability of the copolymer. The mechanical properties test results unveiled that PICC has good mechanical properties. Owing to its excellent mechanical and thermal properties, there is a broad application prospect of the PICC as a green polycarbonate material.