预氧化过程中张力对聚丙烯腈预氧化纤维微缺陷结构的影响

Effect of Tension on the Microvoids Structure of Polyacylonitrile (PAN) Fibers During the Thermal Stabilization Stage

在预氧化过程中,聚丙烯腈（PAN）纤维从有机大分子结构转变为无机乱层石墨结构.预氧化时间、温度及张力影响预氧化纤维的环化度、分子链取向及纤维的皮芯结构,并最终影响碳纤维的性能.其中张力是一个十分重要的因素,研究结果表明,在预氧化和碳化阶段,施加张力可以防止纤维收缩并提高纤维微晶取向,从而提高碳纤维的力学性能.

The effect of tension on the microvoids of polyacylonitrile（PAN） thermal stabilized fibers was investigated by small angle X-ray scattering（SAXS） at Shanghai Synchrotron Radiation Facility（SSRF） at beamline BL16B.All SAXS patterns exhibit a very big anisotropy between the equator and meridian direction.The results indicate that the scattering bodies are elongated and oriented in direction of fiber axis.The quantitative parameters of orientation,length,diameter of the microvoids were obtained.The results show an obvious effect of tension to the microvoids＇ structure——a narrowing of the distribution of the microvoids mis-orientation and a more slender shape of microvoids,compared with the case without tension.