Biodegradable aliphatic poly(carbonate-co-ester)s containing biobased unsaturated double bonds: synthesis and structure-property relationships

A series of aliphatic poly(carbonate-co-ester)s (PBCFs) were successfully synthesized via melt polycondensation of 1,4-butanediol (BD) and dimethyl carbonate (DMC) in the presence of biobased fumaric acid (FA). The prepared unsaturated copolymers had weight-average molecular weights (M-w) in the 4.98 x 10(4) to 8.82 x 10(4) g center dot mol(-1) range and from 1.56 to 1.83 polydispersities. They all had random microstructures. The physical properties of the novel poly(carbonate-co-ester)s, such as melting temperature (T-m) and melting enthalpy ( increment H-m), varied widely depending on their composition. The stiff fumaric acid units in the poly(butylene carbonate) (PBC) chain caused an increase in the glass transition temperature (T-g) and thermal stability. Furthermore, PBCF10 to PBCF20 (with fumaric acid unit content of <19%) contained PBC crystals, while the lattice structure of PBCF40 to PBCF80 (with fumaric acid unit content greater than 37%) was similar to that of the poly(butylene fumarate) (PBF) type. The mechanical properties and biodegradability of the copolymers were also studied.

Automated summary

A series of aliphatic poly(carbonate-co-ester)s were successfully synthesized via melt polycondensation, showing a wide variation in physical properties depending on composition. Fumaric acid units in poly(butylene carbonate) chains increased glass transition temperature and thermal stability. Some copolymers contained PBC crystals, while others had a lattice structure similar to poly(butylene fumarate).