沥青基高取向带状炭纤维的制备及表征

Preparation and Characterization of Highly Oriented Ribbon Shape Pitch-based Carbon Fibers

以萘系中间相沥青为原料,通过熔融纺丝、氧化稳定化、炭化和石墨化处理制得了表面光洁平整的高取向带状纤维,采用红外光谱仪、元素分析仪、X射线衍射仪、拉曼光谱、扫描电子显微镜和偏光显微镜对带状纤维的组成、形貌和微观结构进行了表征.研究结果表明:带状沥青纤维氧化稳定化过程中生成的羧基、羰基、醚等含氧官能团在随后炭化处理过程中消失;带状沥青纤维截面的平均宽度和厚度约为1.6mm和18μm,经炭化和石墨化处理后收缩至1.2mm和9μm;随热处理温度的升高,带状炭纤维(002)晶面的衍射峰逐渐变强,其晶体尺寸逐渐变大;与炭化处理纤维相比,石墨化纤维晶体结构更加完整,沿纤维主表面的取向程度更高.

Using a naphthalene derived mesophase pitch as starting material,high oriented ribbon-shaped carbon fi-bers with smooth and flat surface were prepared by melt-spinning,oxidation stabilization as well as further carboniza-tion and graphitization processes.The composition,morphologies and microstructure of the ribbon-shaped carbon fi-bers treated at various conditions were characterized by elemental analyses,IR spectroscopy,XRD,Raman spectro-scope,scanning electron microscope and polarized-light microscope.The results show that the carboxyl,carbonyl and ether functional groups formed during the oxidizing stabilization process are removed by subsequent carbonization treatment.The width and thickness of the ribbon-shaped fibers at the transverse section decrease from 1.6mm and 18μm of pitch fiber to 1.2mm and 9μm of graphitized carbon fibers,respectively.The relative intensity of the diffrac-tion peak at about 2？ = 26？ corresponding to（002） crystal plane of hexagonal graphite increases with the heat-treatment temperature increasing.This indicates that the crystal size of graphite in this carbon fibers also in-creases in this process.In comparison with the carbonized fibers,the carbon fibers after graphitization treatment dis-play more perfect crystal orientation along the main surface of ribbon-shaped carbon fibers.