不同氧化程度的沥青纤维预氧化与炭化行为  

Effects of the degree of oxidation of pitch fibers on their stabilization and carbonization behaviors

作　　者：彭元硕 杨建校 石奎 郭建光 朱辉[2] 李轩科 PENG Yuan-shuo;YANG Jian-xiao;SHI Kui;GUO Jian-guang;ZHU Hui;LI Xuan-ke(Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology,College of Materials Science and Engineering,Hunan University,Changsha 410082,China;Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]湖南大学材料科学与工程学院,先进炭材料及应用技术湖南省重点实验室,湖南长沙410082 [2]武汉科技大学,煤转化与新型炭材料湖北省重点实验室,湖北武汉430081

出　　处：《新型炭材料》2020年第6期722-730,共9页New Carbon Materials

基　　金：国家自然科学基金青年项目(51702094);湖南省自然科学青年基金项目(2017JJ3014);煤转化与新型炭材料湖北省重点实验室2019年度开放基金资助项目(WKD201908).

摘　　要：以各向同性沥青纤维(IPPF)和中间相沥青纤维(MPPF)为对象,系统研究了它们在不同升温速率和不同预氧化温度下的预氧化过程。通过元素分析,FT-IR,TG-MS和SEM等手段对预氧化纤维(SFs)和炭纤维(CFs)进行了详细的分析表征,探究了沥青纤维的氧化程度对CFs的结构和力学性能的影响规律。结果表明,慢的升温速率有利于沥青纤维的氧化交联,所得到的CFs具有更高的炭化收率和拉伸强度。同时,IPPF和MPPF在270℃进行预氧化时,所制备对应的CFs具有最高的结构性能。另外,SFs的FT-IR图所计算的R1700/R1600值与其对应CFs的炭化收率和拉伸强度存在着良好的映射关系,可以作为一个评估沥青纤维的氧化程度的有效因子。除此之外,氧化不充足的纤维(I-SFs)在炭化过程中释放大量的H2和CH4,造成所得到的CFs出现空心结构,显示低的拉伸强度,尤其I-IPCF较为明显;过度氧化的纤维(E-SFs)则释放大量的CO和CO2,导致其对应的CFs呈现裂缝结构,特别是E-MPCF。因此,纤维预氧化和炭化行为的深入解析与优化对于提升沥青基炭纤维的性能具有重大的意义。The stabilization of isotropic pitch-derived fibers(IPFs)and mesophase pitch-derived fibers(MPFs)in air was performed at different heating rates and with different final stabilization temperatures.The stabilized fibers(SFs)and carbon fibers(CFs)were characterized by elemental analysis,FT-IR,TG-MS and SEM to investigate the influence of the degree of oxidation of the SFs on the microstructures and mechanical properties of the CFs.Results showed that a slow heating rate during stabilization was beneficial to the oxidative cross-linking of PFs,and the corresponding CFs had a higher carbonization yield and tensile strength at the lower heating rate.When both IPF and MPF were stabilized at 270 ℃,the two resulting CFs all reached their optimal performance.In addition,the FTIR peak intensity ratio of the C=O band at about 1700 cm^-1 to the C=C band at 1600 cm^-1 of the SFs had a good relationship to the carbonization yield and tensile strength of the CFs,and this can be used to optimize the degree of oxidation of the SFs.Moreover,insufficiently stabilized fibers released a great deal of H 2 and CH 4,causing some porosity in the resulting CFs with a low tensile strength,especially for the insufficiently stabilized IPCF.While over-stabilized fibers released a large amount of CO and CO2,causing cracked textures in the corresponding CFs,especially in the over-stabilized MPCF.Therefore,this research into the stabilization and carbonization behaviors of pitch fibers has great significance for improving the mechanical properties of pitch-based CFs.

关 键 词：各向同性沥青 中间相沥青 沥青纤维 预氧化 炭纤维 

分 类 号：TQ536.2[化学工程—煤化学工程]