沥青基带状纤维的预氧化研究

Research on pre-oxidation of mesophase pitch-based ribbon fiber

采用熔融纺丝工艺制备中间相沥青基带状纤维,分别于不同温度和不同时间进行氧化稳定化处理,采用红外光谱仪和元素分析测定预氧化纤维官能团和氧含量的变化,并采用扫描电镜和纤维强伸度仪等检测设备研究2 500℃石墨化纤维的结构和性能.实验结果表明：沥青分子在预氧化过程中与氧发生反应,生成了热固性的沥青大分子.氧化温度越高,氧化时间越长,带状纤维的氧含量越高.厚度为～35μm,宽度为～380μm的带状沥青纤维于氧气气氛经220℃下预氧化20h和2 500℃石墨化处理后,其拉伸强度可达1.75GPa,比240℃和260℃预氧化制得的石墨纤维的拉伸强度高.

A melt-spun ribbon shaped pitch-based fiber was pre-oxidized at various temperatures and times. Functional group species and the oxygen content of pre-oxidized fiber were analyzed by FTIR and elemental analyzer. The morphology and property of the fibers graphitized at 2 500TI were characterized by scanning electron microscopy and tensile instrument. After pre-oxidation treatment, the ribbon shaped pitch-based fiber with a thermoplastic character becomes a thermosetting fiber by reaction with oxygen. The oxygen content of pre-oxidized fiber increases with the pre-oxidation temperature and time. Comparison with the graphitized fibers prepared by pre-oxidation at 240 and 260℃, the tensile strength of graphitized fiber prepared by 220T; pre-oxidation is higher. The tensile strength of graphitized fiber treated at 2 500℃, which was oxidized at 220℃ for 20 h, was up to 1.75GPa.