低温热缩聚-溶剂热萃取法制备同性沥青基碳纤维  

Isotropic Pitch-Based Carbon Fibers Prepared by Combining Low Temperature Thermal Polycondensation With Solvothermal Extraction

作　　者：沈国波 刘东[1] SHEN Guobo;LIU Dong(State Key Laboratory of Heavy Oil Processing,College of Chemical Engineering,China University of Petroleum,Qingdao 266400,China)

机构地区：[1]中国石油大学(华东)化学工程学院重质油国家重点实验室,山东青岛266400

出　　处：《石油学报（石油加工）》2022年第6期1271-1280,共10页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：山东省重点研发计划(重大科技创新工程)项目(2020CXGC010308);泰山学者基金项目(ts20190919)资助。

摘　　要：以加氢预处理后的催化裂化油浆为原料,采用低温热缩聚与溶剂热萃取相结合的方法制备同性沥青,并研究了不同热缩聚温度、不同溶剂、不同体积比的正庚烷-甲苯混合溶液对同性沥青的影响。将同性沥青通过熔融纺丝、预氧化、炭化得到同性沥青基碳纤维。采用偏光显微镜、XRD、红外光谱、元素分析、热重分析和扫描电子显微镜等手段对同性沥青基碳纤维进行表征。结果表明:在热缩聚过程中,温度小于400℃能有效避免中间相小球的生成;在溶剂热萃取过程中,随着制备聚合沥青的热缩聚温度升高,正庚烷不溶物软化点也相应提高;随着甲苯含量的提高,混合溶液不溶物收率降低,软化点升高;390℃低温热缩聚,以正庚烷为溶剂进行溶剂热萃取制得的同性沥青软化点达到230℃,熔纺性能好。原丝纤维最佳预氧化条件为:先以升温速率1℃/min升温至180℃,然后以0.5℃/min升至270℃维持30 min;炭化后得到的同性沥青基碳纤维碳质量分数达到94%,拉伸强度达到1.113 GPa。The isotropic pitch was prepared by combining low temperature thermal polycondensation and solvothermal extraction with catalytic cracking slurry pretreated by hydrogenation as a raw material,and the impacts of different thermal polycondensation temperatures,different solvents,and n-heptane-toluene mixture of different volume ratios on the isotropic pitch were studied.The isotropic pitch-based carbon fibers were obtained from isotropic pitch through melt-spinning,pre-oxidation and carbonization.Later,the isotropic pitch-based carbon fibers were characterized by means of PLM(Polarized light microscopy),XRD,FT-IR(Infrared spectroscopy),EA(Elemental analysis),TGA(Thermogravimetric analysis)and SEM(Scanning electron microscope).The results demonstrate that in the process of thermal polycondensation,it can effectively avoid the generation of mesophase microbeads if the temperature is below 400℃;in the process of solvothermal extraction,the softening point of n-heptane insoluble is also improved with the rise of the thermal polycondensation temperature for preparing polymerized pitch;as the content of toluene increases,the insoluble yield of the mixture decreases,while the softening point increases;in the process of low temperature thermal polycondensation at 390℃,the softening point of the isotropic pitch prepared by solvothermal extraction using n-heptane as solvent reaches up to 230℃,indicating good melt-spinning performance.In addition,the best pre-oxidation conditions of as-spun fibers are as follows:firstly heated up to 180℃at the heating rate of 1℃/min,then up to 270℃at the heating rate of 0.5℃/min and maintained for 30 min,in which case the mass fraction of the isotropic pitch-based carbon fibers obtained after carbonization reaches 94%,and the tensile strengthen hits 1.113 GPa.

关 键 词：沥青基 碳纤维 热缩聚 溶剂热萃取 预氧化 

分 类 号：TE65[石油与天然气工程—油气加工工程] TQ343.74[化学工程—化纤工业]