利用差示扫描量热(DSC)、傅里叶变化红外光谱(FT-IR)、拉曼光谱和广角X射线衍射(WAXD)对聚丙烯腈(PAN)原丝在稳定化和低温碳化阶段的结构演变进行了测试和研究。结果表明:空气和氮气气氛中的热稳定性差异主要是由于化学反应差异性造成的,随着热稳定化的进行,发生环化、脱氢和氧化反应,且在230℃以上氧化反应明显增强。拉曼结果显示D带强度减弱,G带强度增强,化学反应使SP3杂化碳转化为SP2杂化碳原子,低温碳化阶段分子链之间交联形成了无定型碳质结构。原始的微晶结构逐渐破坏重组形成新的类石墨碳结构,微晶尺寸变小。
The structural evolution of polyacrylonitrile (PAN) precursor fibers during stabilization and low-temperature carbonization were tested and researched by differential scanning calorimetry (DSC),fourier transform infrared spectroscopy (FT-IR),raman spectroscopy and wide-angle X-ray diffraction (WAXD).The results indicated that the difference in thermal stability of PAN precursor fibers in air and nitrogen atmosphere was mainly caused by the difference of chemical reactions,with the progress of thermal stabilization,cyclization,dehydrogenation and oxidation reactions occurred successfully,and the oxidation reaction was significantly enhanced above 230℃.Raman results showed that the intensity of D-Line weaken,and the intensity of G-Line increased.The chemical reaction lead to more SP3-hybridized carbon converted to SP2.The amorphous polyaromatic carbon structures formed by cross-linking between molecular chains in the low-temperature carbonization stage.The original crystallite structure was gradually destroyed and rearrangement to form new graphite-like carbon network structure,and the crystallite sizes became smaller.
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基金资助
吉林省自然科学基金项目(20190201301JC)
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