【摘要】 为研究多次循环拉伸对氨纶微观结构和尺寸稳定性的影响,选用线密度为622.22 dtex的氨纶丝,分别对其拉伸1 000、4 000、16 000、45 000次。采用傅里叶变换红外光谱、X射线衍射分析、热失重分析、力学性能测试等方法对拉伸后的试验样品进行了表征。结果表明:随着拉伸次数增加,氨纶的氢键化程度一直呈下降趋势;结晶度先上升后下降,拉伸1 000次时得最大值;拉伸次数少于4 000次时,氨纶热稳定性先保持不变,而后下降;力学性能方面,断裂强力与断裂伸长率都是先增后减,拉伸1 000次时都取得最大值;而内耗值一直降低。更多还原

【Abstract】 The 622.22 dtex Spandex was stretched 1 000 times, 4 000 times, 16 000 times and 45 000 timesrespectively to study the influence of cyclic tension on the microstructure and dimensional stability of Span-dex. Fourier transform infrared spectroscopy, X- ray diffraction, thermal gravimetric analysis and mechan-ics performance testing were characterizd the test samples. The results showed that: with the increase in thenumber of stretching, the degree of hydrogen bonding had been declining; the crystallinity rised at first andfell later, and when samples were stretched 1 000 times, the crystallinity reached the maximum value; whenstretching times were fewer than 4 000 times, first the Spandex thermal stability remained constant, then de-creased; the breaking strength and the elongation at break firstly increased and then decreased simultane-ously, while samples were stretched 1 000 times, the breaking strength and elongation at break rearched themaximum value; the value of internal friction kept reducing.更多还原