Chen Liang, Chen Jing, Shen Zhigang, Liu Jie, Wang Xiaoxu
Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology Chao-Yang District Beijing 100029 China
Shanghai Research Institute of Petrochemical Technology Pudong New District Shanghai 201211 China
RSC Adv. 2022 May 4;12(21):13339-13346. doi: 10.1039/d2ra01786e. eCollection 2022 Apr 28.
In this study, the synchronous effects of time and temperature on the radial structural differences of polyacrylonitrile (PAN) fibres during thermal stabilization were investigated. For each sample to achieve equal densities (∼1.36 g cm), PAN fibres were thermally stabilized for various times between 8-32 min and at corresponding temperatures of 279-252 °C, which was considered to give a synchronous processing adjustment as a time-temperature integral (TTI). Besides, a previously developed mathematic model was utilized to quantitatively evaluate the differences in the radial heterogeneous structures of the stabilized PAN fibres as a function of TTI. It was found that several structural parameters (, the stabilization degrees, the present crystallinities, and the orientation degrees) of PAN chains in the skin regions that mainly determine the fibres' overall performances were dramatically different from those in the core regions. Meanwhile, based on the TTI model, these skin-structure parameters demonstrated a strong correlation with the tensile properties of the resultant carbon fibres. However, while the stabilized PAN fibres had equal densities, their structural parameters, as well as the properties of the resultant carbon fibres, were obviously different.
在本研究中，研究了时间和温度对聚丙烯腈（PAN）纤维在热稳定化过程中径向结构差异的同步影响。为使每个样品达到相同密度（约1.36 g/cm），将PAN纤维在8 - 32分钟的不同时间以及279 - 252°C的相应温度下进行热稳定化处理，这被视为作为时间 - 温度积分（TTI）的同步工艺调整。此外，利用先前开发的数学模型来定量评估稳定化PAN纤维径向非均相结构随TTI的差异。结果发现，主要决定纤维整体性能的皮层区域中PAN链的几个结构参数（稳定化程度、当前结晶度和取向度）与芯层区域的参数有显著差异。同时，基于TTI模型，这些皮层结构参数与所得碳纤维的拉伸性能表现出强烈的相关性。然而，虽然稳定化的PAN纤维密度相同，但其结构参数以及所得碳纤维的性能却明显不同。
