预氧化拉伸对PAN基碳纤维结构和性能的影响

Effect of drawing process on structure and properties of PAN-based carbon fiber during preoxidation

借助X射线衍射、元素分析等表征手段,研究了聚丙烯腈(PAN)纤维在预氧化过程中拉伸对纤维孔隙结构、预氧丝氧含量和最终碳纤维力学性能的影响。结果表明:随着拉伸倍数的增大,PAN预氧丝的平均孔径和孔隙率均减小;经一定拉伸后PAN基碳纤维的强度和模量均有所增加,但当拉伸到一定程度后,PAN预氧丝的氧含量呈下降趋势,纤维未形成稳定的耐热梯形结构,PAN基碳纤维力学性能显著下降。

The effects of the drawing process on the fiber pore structure, the oxygen content of preoxidized fiber and the mechanical properties of the final carbon fiber were studied during the preoxidation of polyacrylonitrile （PAN） fiber by X-ray diffraction and elementary analysis. The results showed that the average pore size and void content of PAN preoxidized fiber were beth decreased while increasing the draw ratio. The strength and modulus of PAN-based carbon fiber were enhanced in some degree after a certain drawing. The oxygen content of the PAN preoxidized fiber appeared a downward tendency under an excessive drawing, thus the formation of a steady heat resistant ladderlike structure of the fiber became impossible, and the mechanical properties of the PAN-based carbon fiber were greatly impacted.