摘要
预氧纤维结构及其分布直接影响炭纤维的性能,优化预氧结构径向分布,构建预氧结构与炭纤维力学性能的关系,对制备高性能炭纤维具有指导意义。本文采用固体核磁、光学显微镜、热失重等表征方法,通过温度控制预氧化反应速率,研究预氧化反应速率对纤维结构和径向分布及炭纤维性能的影响。结果表明,整体提高预氧化反应速率,在促进预氧结构向纤维更深区域扩展的同时,也导致含氧结构增加较多,热稳定性降低,影响炭纤维的性能;而提高预氧化初期反应速率,有效改善预氧结构径向分布的同时纤维含氧结构增加较少,热稳定性提高,最终炭纤维的石墨化程度和致密性较高,力学性能显著提升,获得一种具有高强中模特征、直径相对较大的炭纤维。
The radial structure of polyacrylonitrile fibers oxidized before carbonization and its distribution directly affect the per-formance of the resulting carbon fibers.Optimizing the radial distribution of the oxidized structure and establishing a relationship between this structure and the mechanical properties of the final carbon fibers will help optimize the oxidation conditions for the pre-paration of high-performance carbon fibers.Solid-state nuclear magnetic resonance spectroscopy,optical microscopy,thermogravi-metric analysis,and mechanical tests were used to investigate the effect of the oxidation reaction rate on the radial distribution of the structure of the oxidized fibers and the mechanical properties of the resulting carbon fibers.The oxidation reaction rates were con-trolled by regulating the oxidation temperature gradient.Results show that the degree of oxidation increases with both the average and initial oxidation rates.By increasing the average oxidation reaction rate,the oxidized structure penetrates deeper into the core re-gion of the fibers,the content of oxygen-containing functional groups increases,the thermal stability of the fibers decreases,and the degree of graphitization of the final carbon fibers increases,but the density of the fibers is decreased and their mechanical properties are degraded.Compared with sample obtained with the lower initial oxidation rate,the number of oxygen-containing functional groups,thermal stability,degree of graphitization and density of the final carbon fibers of the sample with the higher initial oxidation rate are higher,and its tensile strength and modulus are respectively 4.2%and 2.2%higher.A new type of carbon fiber with high strength,medium modulus and a relatively large diameter is obtained under the optimized oxidation conditions.
作者
王云峰
王一苇
徐樑华
王宇
WANG Yun-feng;WANG Yi-wei;XU Liang-hua;WANG Yu(Beijing University of Chemical Technology,Beijing 100029,China;National Carbon Fiber Engineering Technology Research Center,Beijing 100029,China;Carbon Fiber and Functional Polymer Key Laboratory of Ministry of Education,Beijing 100029,China)
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
北大核心
2021年第4期827-834,共8页
New Carbon Materials
基金
装备预研教育部联合基金(6141A02033231,6141A02033223)
国防基础科研计划项目(JCKY2018110C139)
中央高校基本业务费项目(JD2012).
关键词
预氧纤维
反应速率
径向分布
预氧温度
力学性能
Pre-oxidized fibre
Reaction rate
Radial distribution
Pre-oxidation temperature
Mechanical properties
