Crystallization and Morphology in a 30/70 Poly(ethylene succinate-co-6 mol % butylene succinate)/Poly(ethylene oxide) Blend

Crystallization and morphology were studied in a 30/70 poly(ethylene succinate- co -6 mol % butylene succinate)/poly(ethylene oxide) (P(ES- co -6 mol % BS)/PEO) blend in this work. Depending on the crystallization conditions, including one-step and two-step crystallization, both components may crystallize separately or simultaneously. P(ES- co -6 mol % BS) and PEO crystallized separately via two-step crystallization. When the crystallization temperature was between the melting points of the two components, both the spherulitic growth rate and the overall crystallization rate of P(ES- co -6 mol % BS) decreased with increasing crystallization temperature; moreover, they were slower in the blend than in neat P(ES- co -6 mol % BS) at the same crystallization temperature. When the crystallization temperature was further lowered below the melting point of PEO, PEO crystallized only as tiny crystals within the P(ES- co -6 mol % BS) spherulites formed earlier, while its overall crystallization rate was increased significantly in the presence of the P(ES- co -6 mol % BS) crystals. In the case of simultaneous crystallization, growth of both P(ES- co -6 mol % BS) and PEO spherulites and the formation of interpenetrated spherulites were observed in a wide crystallization temperature range via one-step crystallization.