预氧化过程中张力对中间相沥青纤维取向结构的影响

Effect of tension on the orientation structure of mesophase pitch fibers in stabilization process

通过熔融纺丝制备相同条件中间相沥青原丝,分别施加3.6,10.8 MPa张力进行预氧化处理,用XRD,SEM,HRTEM等手段对两组纤维的取向结构进行研究。结果表明:预氧化过程中施加张力有利于提高纤维取向度,张力越大,纤维取向度越高,微晶沿纤维轴向排列更加整齐有序,晶面间距较小,微晶尺寸较大;经2 800℃石墨化处理后,施加3.6 MPa和10.8 MPa张力纤维取向度分别达到94.76%和95.25%。

The as-spun mesophase pitch fibers prepared by melt spinning process were stabilized under different tensions of 3.6 MPa and 10.8 MPa respectively. The orientation structure of the two group fibers were studied by means of XRD, SEM, HRTEM. The results show that applying stress in the process of stabilization is conducive to improving the orientation degree of fibers. The greater the stress applied, the higher the orientation degree, and mierocrystalline arranged more orderly along the fiber axis with the smaller lattice spacing and ther the larger erystallite size. After graphitized at 2 800℃, the orientation degree of the fibers that imposed 3.6 MPa and 10.8 MPa stress were 94.76% and 95.25%,respectively.