不同温度下PET／PTT长丝的结构和性能

Structures and properties of PET/PTT filament at different temperatures

因温度是影响PET/PTT双组分长丝卷曲性能的最关键因素,研究了温度对PET/PTT长丝结构和性能的影响。结果表明:随温度升高,纤维的卷曲收缩率增加,卷曲伸长率减小。无论是在干热还是湿热条件下,温度升高均加速纤维的解取向,各单组分纤维和PET/PTT双组分长丝的声速取向因子均降低,尤其是双组分长丝的声速取向因子迅速降低。同时,各单组分纤维的结晶度随温度升高而增加,但PET/PTT双组分长丝中各单组分的结晶度却随着温度升高而显著降低。结晶度降低加速了各组分的解取向程度,导致纤维长度在宏观上发生收缩,且由分子链解取向导致的收缩率逐渐增加,而由双组分收缩差导致的收缩率逐渐减小。

Temperature is the key factor which affects the crimp appearance of PET/PTT filament. The effect of temperature on the structures and properties of PET/PTT filament is studied. The results indicate that the crimp shrinking rate of PET/PTT fiber increases and the crimp elongation rate decreases with temperature rising. No matter under dry or wet thermal conditions, the increasing of temperature accelerates the orientation of the fibers; the sonic orientation factors of both two monocomponent fibers and PET/PTT bicomponent fiber decrease, especially, the PET/PTT bicomponent fiber; also, the crystallinities of the two monocomponent fiber increase while the crystallinity of bicomponent fiber decreases significantly. Decrease in crystallinity leads to the rapid decrease of fiber orientation factor and makes the length of the fiber shrink. The shrinkage rate from disorientation increases and the crimp shrinkage resulted from the shrinkage differential of two components decreases.