沥青和PAN的静电纺碳纳米级纤维膜的制备及表征

Preparation and characterization of electrospun carbon nanoscale fiber membranes based on pitch and PAN

利用N,N二甲基甲酰胺(DMF)为溶剂、滚轴为接收装置,通过静电纺丝法制备聚丙烯腈(PAN)和可纺沥青(SP)共混前驱体纳米级纤维膜,再对其进行预氧化和碳化,制备碳纳米级纤维膜,以有效降低碳纤维生产成本。结果表明在保持纺丝液质量浓度不变的条件下,纤维直径随SP质量分数的增大而减小。制得的纳米级纤维膜具有一定取向度,且经预氧化和碳化处理后,纳米级纤维膜的取向度得到提升;碳化后,沿纤维取向方向的电导率约为垂直于纤维取向方向的3倍。预氧化过程中,纳米级纤维膜因纤维大分子上形成醚键和羰基而质量增加,后又因交联和环化而质量减少。预氧化后,—C≡N环化为C=N,分子结构变得更规整,且颜色发生变化。碳化后,纤维中C元素质量分数达96.89%,结晶度比前驱体纤维高出9.94%。

Using N,N-Dimethylformamide(DMF)as solvent and roller as receiving device,the precursor nanoscale fiber membranes of polyacrylonitrile(PAN)and spinnable pitch(SP)blends were prepared by electrospinning method,and then the carbon nanoscale fiber membranes were prepared by pre-oxidation and carbonization,in order to reduce the production cost of carbon fibers effectively.The results showed that,the fiber diameter decreased with the increase of SP mass fraction under the condition of keeping the mass concentration of spinning solution constant.The nanoscale fiber membranes had a certain degree of orientation,and the degree of orientation of the nanoscale fiber membranes was improved after pre-oxidation and carbonization.After carbonization,the conductivity along the fiber orientation was about 3 times than that perpendicular to the fiber orientation.During the pre-oxidation process,the weight of nanoscale fiber membranes increased due to the formation of ether bond and carbonyl group on the fiber macromolecules,and then lost weight due to crosslinking and cyclization.After pre-oxidation,the—C≡N was cycled to C=N,and the molecular structure became more regular,and the color changed.After carbonization,the mass percentage of C element in the fiber reached 96.89%,and the crystallinity was 9.94%higher than that of the precursor fiber.