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首页> 外文期刊>Journal of Applied Polymer Science >Evolution of the crystalline structure and cyclization with changing tension during the stabilization of polyacrylonitrile fibers
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Evolution of the crystalline structure and cyclization with changing tension during the stabilization of polyacrylonitrile fibers

机译：聚丙烯腈纤维稳定过程中晶体结构的演变和随张力变化的环化

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The effects of tension on the crystalline structure and cyclization of polyacrylonitrile fibers during stabilization were investigated. The degree of cyclization was measured by Fourier transform infrared spectroscopy and differential scanning calorimetry. The crystalline structure was characterized by wide-angle X-ray diffraction. When the fibers were heat-treated at temperatures between 175 and 218 degrees C, the tension mainly affected the cyclization in the amorphous regions through changes in the spatial distance of the chain segments; this led to a relatively higher cyclization degree under moderate tension. When the temperatures ranged from 226 to 232 degrees C, the reactions extended to the crystalline regions. The chemical bonds became greater in the cross section of the fibers, and this was caused by cyclization structures formed in the former stage. Therefore, the optimum tension was higher than in the prior temperature range. At higher temperatures ranging from 238 to 270 degrees C, a crosslinked structure formed, so the optimum tension increased continually. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42182.
机译：研究了在稳定过程中张力对聚丙烯腈纤维晶体结构和环化的影响。通过傅里叶变换红外光谱和差示扫描量热法测量环化程度。晶体结构通过广角X射线衍射表征。当纤维在175到218摄氏度之间的温度下进行热处理时，张力主要通过链段空间距离的变化影响无定形区域的环化作用。这导致在中等张力下环化程度相对较高。当温度在226至232摄氏度之间时，反应会扩展到结晶区域。在纤维的横截面中，化学键变得更大，这是由于前阶段形成的环化结构引起的。因此，最佳张力高于先前的温度范围。在238至270摄氏度的较高温度下，形成了交联结构，因此最佳张力不断增加。 （c）2015 Wiley Periodicals，Inc. J. Appl。 Polym。科学2015，132，42182。

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