Poly(ethylene succinate)-b-poly(butylene succinate) Multiblock Copolyesters: The Effects of Block Length and Composition on Physical Properties

Poly(ethylene succinate)-b-poly(butylene succinate) (PES-b-PBS) multiblock copolymers with different block lengths and compositions were synthesized, and their chemical structure, molecular weights, and polydispersity index of the copolymers were characterized by H-1 NMR and GPC, respectively. The miscibility and crystallization of PES and PBS blocks in the copolymers were investigated by DSC. The results suggested that PES and PBS blocks are miscible in copolymers with shorter block lengths, while they are partially miscible in those with longer block lengths. The crystallization of PBS blocks were depressed with an increase in PES content due to the diluent effect, and that of PES blocks was largely restricted when its content was less than the PBS block, while that was improved when its content was more than that of the PBS block due to the nucleation effect of previously crystallized PBS. The results of tensile test suggest that all the copolymers showed excellent mechanical property.