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Preparation and Carbonization of Ultra-Oriented Poly(acrylonitrile) Fibers: Effect of Stereoregularity

超取向聚丙烯腈纤维的制备和碳化：立构规整性的影响

基本信息

批准号：
11650934
负责人：
TETSUO Kanamoto
金额：
$ 2.43万
依托单位：
Tokyo University of Science
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Uniaxial drawing of isotaotic and atactivc poly(acrylonitrile)(iso-PAN and at-PAN) were studied. Dried gel films were initially drawn by solid-state coextrusion (first-stage draw) to an extrusion draw ratio of 16, followed by a further tensile draw at 100-200℃(second-stage draw). The temperature for optimum second-stage draw of iso-PAN, 130-140℃, was significantly lower than that (160-180℃) of at-PAN, reflecting their crystal softening temperatures 〓00vs. 150℃). The maximum achieved total draw ratios were comparable for these PANs. Although, the maximum tensile modulus, as well as modulus at a given DR, was slightly higher for iso-PAN than for at-PAN (28.5 vs. 23.0 GPa), the maximum tensile strength was comparable for each PAN, at 0.90 GPa. The shapes of stress/strain curves for fibers were significantly different between iso- and at-PAN reflecting their different chain conformations: a predominantly 3/1 helical con formation for iso-PAN and planar zigzag and helical sequences for at-PAN.SAXS of at-PAN fibers prepared by solid-state coextrusion of a nascent PAN formed under controlled conditions has been examined. Although solution-spun PAN fibers and their drawn products generally show no X-ray long-period scattering, the nascent PAN and the fibers prepared from it exhibited a clear SAXS maximum, depending on the extrusion temperature(T_<ext>) and draw ratio (EDR). These observations reveal that the absence or presence of an X-ray long-period scattering for PAN fibers depends on the initial morphology and the drawing variables.

研究了等规和非活性聚丙烯腈（iso-PAN和at-PAN）的单轴拉伸。干燥的凝胶膜首先通过固态共挤出（第一阶段拉伸）拉伸至挤出拉伸比为16，然后在100-200℃进一步拉伸（第二阶段拉伸）。 iso-PAN的最佳第二阶段拉伸温度为130-140℃，明显低于at-PAN的最佳第二阶段拉伸温度（160-180℃），反映了它们的晶体软化温度〓00vs。 150℃）。这些 PAN 所达到的最大总拉伸比是相当的。尽管 iso-PAN 的最大拉伸模量以及给定 DR 下的模量略高于 at-PAN（28.5 与 23.0 GPa），但每种 PAN 的最大拉伸强度相当，均为 0.90 GPa。纤维的应力/应变曲线形状在 iso-PAN 和 at-PAN 之间显着不同，反映出它们不同的链构象：iso-PAN 主要为 3/1 螺旋构象，而 at-PAN 为平面锯齿形和螺旋序列。对在受控条件下形成的新生 PAN 进行固态共挤出制备的 at-PAN 纤维的 SAXS 进行了检查。尽管溶液纺丝 PAN 纤维及其拉伸产品通常不显示 X 射线长周期散射，但新生 PAN 和由其制备的纤维表现出明显的 SAXS 最大值，具体取决于挤出温度 (T_<ext>) 和拉伸比 (EDR)。这些观察结果表明，PAN 纤维是否存在 X 射线长周期散射取决于初始形态和拉伸变量。