【摘要】 中间相沥青纤维的预氧化主要依赖沥青分子之间的氧化交联,包括含氧官能团的生成和脱除,因而研究纤维预氧化过程中的交联机理对制备高性能中间相沥青基碳纤维尤为重要。采用元素分析、核磁共振以及傅里叶变换光谱对中间相沥青预氧化过程中的官能团结构以及转变进行分析。结果表明,预氧化过程中首先生成一些热稳性较低的羟基、脂肪醚基等含氧官能团,随着氧化反应的进行,这些官能团逐步转变为热稳定较高的羧基、羰基以及芳醚,交联度增强,纤维内形成以氧为连接点的交联网络。同时应力测试表明,随着预氧化反应的进行,分子内部发生化学反应形成交联结构,应力增大,与上述预氧化过程中官能团转变结论相一致。更多还原

【Abstract】 The stabilization of mesophase pitch fibers mainly depends on oxidative cross-linking between pitch molecules, including the generation and removal of oxygen containing functional groups. Therefore, it is very crucial for the preparation of high-performance mesophase pitch based carbon fibers to study the cross-linking mechanism of stabilization process. The structure of functional group and transition in the process of stabilization were analyzed by elemental analysis(EA), nuclear magnetic resonance(NMR) and Fourier infrared spectrum analyzer(FT-IR) in this study. The results indicate that some low thermal stability oxygen containing functional groups such as hydroxyl, aliphatic ether and so on are first generated in the stabilization process. Moreover, as the oxidation reaction proceeds, these functional groups gradually transform into high thermal stability the carboxyl, carbonyl and aryl ethers, and cross-linking are increased. As a result, cross-linking network is formed by the oxygen as cross-linking points in the fiber. Besides, stress test indicates that as the oxidation reaction proceeds, chemical reaction inside the molecule forms the structure of cross-linking, which results in the increase of stress. This is consistent with the conclusion of transition of functional groups in the process of stabilization in the above.更多还原