Thermal oxidative stabilization (TOS) behaviors of polyacrylonitrile (PAN) (co)polymers with different comonomers, such as itaconic acid (IA), methacrylic acid (MA), methyl methacrylate (MMA), vinyl acetate (VA), and VA/IA mixture, were investigated through Fourier transform infrared spectroscopy analysis to quantitatively determine the role of the comonomers. Poly(acrylonitrile-co-MMA) exhibited slow progress of TOS, indicating general radical mediated TOS processes. Facilitated stabilization behaviors of poly(acrylonitrile-co-IA) (PAIA) and poly(acrylonitrile-co-MA) (PAMA) were observed, indicating additional ionic initiating activity of the comonomer carboxylic units. Poly(acrylonitrile-co-VA) exhibited a certain induction period, followed by an accelerated TOS in the later stage, indicating effective in situ generation of acetic acid through the degradation of vinyl acetate units during the TOS. Interestingly, the PAN-based terpolymer containing both VA and IA exhibited not only the most efficient but also the fastest progress of cyclization among the (co)polymers. The results demonstrated a synergistic combination of VA and IA in terms of TOS characteristics, likely stemming from the cascade initiation activity of the carboxylic acid groups from IA and VA. The results suggested the importance of the type and combination of comonomers as a crucial factor to control the TOS processes, providing technical information to design an optimum precursor for better carbon materials.

具有衣康酸（IA），甲基丙烯酸（MA），甲基丙烯酸甲酯（MMA），乙酸乙烯酯（VA）和VA / IA等不同共聚单体的聚丙烯腈（PAN）（共）聚合物的热氧化稳定（TOS）行为通过傅立叶变换红外光谱分析法对混合物进行了研究，以定量确定共聚单体的作用。聚（丙烯腈-共-MMA）显示出TOS的进展缓慢，这表明一般的自由基介导的TOS过程。聚（丙烯腈的促进稳定行为共-IA）（PAIA）和聚（丙烯腈-共观察-MA）（PAMA），表示共聚单体羧酸单元的另外的离子引发活性。聚（丙烯腈共-VA）表现出一定的诱导期，随后在后期加速TOS，表明在TOS期间通过乙酸乙烯酯单元的降解可有效地原位生成乙酸。有趣的是，在（共）聚合物中，同时含有VA和IA的PAN基三元共聚物不仅显示出最有效的环化反应，而且显示出最快的环化进展。结果表明，就TOS特性而言，VA和IA具有协同作用，这可能是由于IA和VA的羧酸基团的级联引发活性所致。结果表明，共聚单体的类型和组合作为控制TOS工艺的关键因素的重要性，为设计更好的碳材料的最佳前体提供了技术信息。