高性能沥青纤维预氧化工艺及机理研究

Study on Preoxidation Process and Mechanism of High Performance Mesophase Pitch Fiber

通过FT-IR,TG-MS,EDS等测试手段研究了中间相沥青纤维在预氧化过程中温度、时间与最终炭纤维显微结构以及其导电导热和力学性能的关联。结果表明,在240℃,6 h的氧化条件下,炭化纤维预氧化进行比较充分。经过炭化以及3 000℃石墨化热处理后,纤维拉伸强度和杨氏模量可分别达到2.54GPa,650 GPa,热导率可以达到860 W/(m·K)。通过机理分析得出,纤维在预氧化可以分为4个阶段。随着氧化的深入,纤维截面形态从皮芯结构向辐射状、大角度劈裂辐射状及辐射状疏松结构演变。

By means of FT-IR,TG-MS and EDS,the relationship between the pre oxidation temperature and time of mesophase pitch fiber and the final carbon fiber microstructure and its conductivity,thermal conductivity and mechanical properties were studied.The results show that carbonized fiber cross-section radial uniform distribution of oxygen concentration is on the oxidation conditions of 240℃,6 h.After Carbonization and 3 000℃of graphitization heat treatment,the tensile strength and Young’s modulus can reach 2.54 GPa and 650 GPa respectively and the thermal conductivity can reach 860 W/(m·K).Through mechanism analysis,the fiber pre oxidation experiences four stages.With the in-depth of oxidation,fiber cross-section shape changes from the skin core structure to radial and large angle splitting radial and radial porous structure.