聚丙烯腈纤维预氧化过程微孔缺陷的演变（英文）

Evolution of Microvoid Defects of PAN Fibers during Stabilization

应用小角X射线散射法研究聚丙烯腈纤维预氧化过程微孔缺陷的演变。建立模型计算微孔缺陷的长度L,横截面尺寸lp,取向角Beq以及相对体积Vrel等参数。研究预氧化温度对微孔缺陷的影响,结果表明Beq和Vrel随着温度的升高不断增加。在预氧化温度220℃下,微孔长度L达到最大值,微孔取向性最好。研究牵伸率对微孔缺陷的影响,结果表明牵伸有利于微孔缺陷的取向,但牵伸率越大,微孔体积越大。研究预氧化过程微观缺陷的演变对于高性能碳纤维的制备具有指导作用。

Evolution of microvoid defects of PAN fibers during stabilization was studied using small angle X-ray scattering(SAXS). The parameters length L, average chord length lp in the cross section, orientation angle Beq and relative volume Vrel of microvoid defects were computed. The results show that during stabilization between 160 °C and 300 °C, the values of orientation angle Beq and relative volume Vrel of microvoid defects increase with the rising of temperature. The value of length L increases and reaches to maximum at the temperature of 220°C. Stretching ratio is another critical factor during stabilization. The results indicate that stretching is helpful for the orientation of microvoid defects. However, the value of relative volume Vrel of microvoid defects increases with the rising of stretching ratio. The results give a deep understanding of the microstructure evolution in the PAN fibers during stabilization, which is important for the preparation of high performance carbon fibers.