Crystallization Kinetics and Morphology of Novel Biodegradable Poly(hexamethylene succinate-co-3 mol % ethylene succinate) with Low and High Molecular Weights

Abstract

The crystal structure, basic thermal behavior, nonisothermal melt crystallization behavior, overall isothermal melt crystallization kinetics, and spherulitic morphology of novel biodegradable poly(hexamethylene succinate-co-3 mol % ethylene succinate) P(HS-co-3 mol %ES) with low and high molecular weights, i.e., PHES12k and PHES58k were investigated. Both PHES12k and PHES58k have the same crystal structure as neat poly(hexamethylene succinate). The glass-transition temperatures are almost the same for both PHES12k and PHES58k. The melt point temperatures and crystallization peak temperatures are higher in PHES12k than in PHES58k; however, the equilibrium melting point temperatures are lower in PHES12k than in PHES58k. With an increase in crystallization temperature, the overall isothermal melt crystallization rates decrease gradually for both PHES12k and PHES58k; moreover, at the same crystallization temperature, PHES12k crystallizes faster than PHES58k. The spherulitic growth rates are faster in PHES12k than in PHES58k, while the nucleation densityof the spherulites is lower in PHES12k than in PHES58k.