Abstract: The crystalline morphology and the affecting factors of poly(ethylene terephthalate)(PET)/poly(trimethylene terephthalate)(PTT) were studied by thermal plataform polarized light microscope.The results showed that the induction period of PET/PTT alloy became longer with the ascent of the isothermal crystallization temperature, and the dimensions of each specimen spherulite growed larger with the extension of the time within the range of the time observed , and the line growth rate and the dimensions of the specimen spherulites increased with the increment of PTT content. When the morphology of isothermal crystallization spherulites at different temperatures was compared, it can be concluded that the dimensions of the PET/PTT(100/0) specimen spherulites were largest at 190℃, the dimensions of the PET/PTT(40/60) and PET/PTT(0/100)specimen spherulites were largest at 180℃.And the complicated ribbon sphrulites appeared when PET/PTT(0/100)specimen crystallized isothermally.

Key words: poly(ethylene terephthalate), poly(trimethylene terephthalate), alloy, nonisothermal crystallization