Synthesis and properties of novel biodegradable poly(butylene succinate-co-decamethylene succinate) copolyesters from renewable resources

Through a two-step melt polycondensation method, three novel poly(butylene succinate-co-decamethylene succinate) (PBDS) copolyesters containing low decamethylene succinate (DS) comonomer compositions from 12 to 33 mol% and its homopolymer poly(butylene succinate) (PBS) were successfully synthesized. The molecular weight, composition, basic thermal behaviors, crystal structure, and mechanical properties of PBDS with different DS compositions and PBS were studied. PBDS and PBS had high thermal stability and the same crystal structure, but the PBDS copolymers showed smaller crystallinity than PBS. The glass transition temperature, melting point temperature, nonisothermal melt crystallization peak temperature, and equilibrium melting point temperature of PBDS were smaller than those of PBS and obviously decreased with the increase of the DS composition. The composition dependence of melting point temperature for the PBDS copolymers was well described by the Flory equation. With increasing the DS composition, the elongation rate at break of PBDS increased significantly, while the yield stress, Young modulus, and tensile strength decreased gradually.