Dong Ruihao, Wu Jianglu, You Ting, Cao Weiyu
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
The Key Laboratory of Education Ministry on Carbon Fiber and Functional Polymer, Beijing University of Chemical Technology, Beijing 100029, China.
Materials (Basel). 2021 Dec 21;15(1):30. doi: 10.3390/ma15010030.
The generated sp hybrid conjugate structure of a C atom, which resulted from the chemical reaction affected by temperature and time, is an effective six-membered ring planar structure of the final carbon fiber. This kind of hybrid conjugate structure determined the formation of the final structure and mechanical properties of carbon fiber. In this paper, the formation and evolution of sp hybrid conjugated structures of PAN precursor during thermal stabilization were investigated by Raman, UV-vis and C-NMR methods. The results indicated that with the increase of stabilization temperature, the degree of the sp hybrid conjugated structure of stabilized PAN fiber increases "linearly", while the content of the sp hybrid carbon atoms increases with "S-type". The final sp hybrid conjugated ring structure is mainly composed of single-ring, double-ring, triple-ring, and double-bond structures. Compared with the time factor, the temperature effect plays a decisive role in the formation of the sp hybrid conjugate structure.
由温度和时间影响的化学反应产生的C原子的sp杂化共轭结构，是最终碳纤维的一种有效的六元环平面结构。这种杂化共轭结构决定了碳纤维最终结构的形成和力学性能。本文采用拉曼光谱、紫外可见光谱和碳核磁共振方法研究了聚丙烯腈（PAN）前驱体在热稳定化过程中sp杂化共轭结构的形成与演变。结果表明，随着稳定化温度的升高，稳定化PAN纤维的sp杂化共轭结构程度呈“线性”增加，而sp杂化碳原子的含量呈“S型”增加。最终的sp杂化共轭环结构主要由单环、双环、三环和双键结构组成。与时间因素相比，温度效应在sp杂化共轭结构的形成中起决定性作用。
