超临界CO2流体处理时间对二醋酯纤维结构与性能的影响

为将超临界CO₂流体应用于二醋酯纤维的功能化加工,赋予二醋酯纤维高附加值,借助扫描电子显微镜、傅里叶红外光谱仪、X射线多晶衍射仪、热重差热分析仪、万能材料试验机探讨了超临界CO₂流体处理时间对二醋酯纤维表观形态、化学结构、聚集态结构及热性能和拉伸断裂性能的影响。结果表明:经超临界CO₂流体处理60、90、120 min后,二醋酯纤维表面颗粒状杂质被去除,其分子链排列规整度下降,结晶度由未处理纤维的39.41%分别下降至35.33%、31.57%、36.10%,纤维断裂强力呈先下降后增加趋势;当处理时间为120 min时,二醋酯纤维分子链间氢键作用强度略微降低,其熔点基本不变,高温下纤维质量损失率由未处理纤维的89.52%增加至95.66%。

Effects of supercritical CO2 fluid treatment time on structure and properties of diacetate fibers

In order to functionally finish diacetate fibers using supercritical CO₂ fluid technology, which gives high added value to diacetate fibers, the effects of supercritical CO₂ fluid treatment time on surface morphology, chemical structure,aggregation structure,thermal property and tensile strength of diacetate fiber were investigated by means of scanning electron microscope, Fourier infrared spectrometer, X-ray polycrystalline diffractometer, thermogravimetric analyzer, differential scanning calorimetry and universal strength tester. Results show the particulate impurities are removed on the surface of the diacetate fiber treated by supercritical CO₂ fluid for 60, 90 and 120 min, and the order of the molecular chain decreased, as well as the crystallinity of diacetate fibers decreases from 39.41% of untreated fiber to 35.33%, 31.57%, 36.10% respectively, and the breaking strength of fiber decreased first and then increased. After 120 min of supercritical CO₂ fluid treatment, the breaking strength of hydrogen bond between molecular chains of diacetate fibers shows a slight decrease. The melting point of the diacetate fibers is basically the same, and the mass loss rate of fiber increase from 89.52% to 95.66% in high temperature.