Transesterification-induced evolution of structure and morphology in poly(trimethylene terephthalate)/poly(butylenes succinate) blends

摘要

The evolution of the structure and morphology in poly(trimethylene terephthalate)/poly(butylene succinate) (PTT/PBS) blends induced by transesterification between PTT and PBS at different blending temperatures for 2h and various times at 270°C was investigated. By control of the extent of transesterification, the degree of randomness, crystallization, morphology, and tensile properties of the blends could be modulated. The results indicated that the degree of randomness of the blends increased by increasing the blending temperature above 260°C and blending time, leading to the formation of copolyesters. The crystallization of the blends was restricted by the increase of blending temperature and time, shown by broad reflection peaks in X-ray spectra and less perfect spherulites as observed by polarized optical microscopy (POM), which was due to the increase of the degree of randomness. The elongation at break increased by increasing the blending time and temperature, accompanied by a decrease of tensile strength and elastic modulus, showing a dependence on the degree of randomness caused by the transesterification.