Synthesis, thermal and mechanical properties of novel biobased, biodegradable and double crystalline Poly(butylene succinate)-b-Poly (butylene sebacate) multiblock copolymers

Novel biobased, biodegradable, and double crystalline poly(butylene succinate)-b-poly(butylene sebacate) (PBS-b-PBSe) multiblock copolymers were successfully synthesized in this research from dihydroxyl terminated PBS-diol and PBSe-diol through a chain extension reaction using hexamethylene diisocyanate as a chain extender. PBS-b-PBSe multiblock copolymers still showed high thermal stability, with the thermal decomposition temperature of above 340 degrees C. In the PBS-b-PBSe multiblock copolymers, both PBS and PBSe blocks were miscible in the amorphous phase and crystallized separately in the crystalline phase. The melt crystallization temperature of one block gradually decreased with increasing the other block content; however, the melting point temperature of each block only decreased slightly, compared with those of PBS and PBSe homopolymers. The crystal structure study revealed again that both blocks crystallized separately in the copolymers. The tensile mechanical properties of PBS-b-PBSe were remarkably improved. The elongation at break significantly increased from 51.7 +/- 0.8% for PBS homopolymer to 673.6 +/- 22.2% for PBS-b-PBSe when the weight content of PBSe block was about 40%.

Automated summary

Novel biobased and biodegradable PBS-b-PBSe multiblock copolymers were successfully synthesized with high thermal stability. The two blocks crystallized separately in both amorphous and crystalline phases. The mechanical properties of the copolymers were significantly improved compared to homopolymers.