甲基对聚邻甲苯胺结构和性能的影响

THE INFLUENCE OF METHYL GROUP ON THE STRUCTURE AND PROPERTIES OF POLY-O-METHYLANILINE

用化学氧化法制备导电聚苯胺(PAN I)和聚邻甲苯胺(POT)。借助FT-IR和UV-V is等分析手段研究了两种导电聚合物在结构和性能上的差异。结果表明,聚邻甲苯胺中甲基的空间位阻效应远大于诱导效应和超共轭效应。空间位阻导致聚邻甲苯胺的分子链发生扭转,链间间距增加,电荷的链内扩散和链间跃迁变得困难,因此其导电性低于聚苯胺。此外,由于聚邻甲苯胺存在甲基的空间位阻效应,它的UV-V is和FT-IR的部分吸收峰与聚苯胺相比发生紫移。

Conducting polyaniline （PANI） and poly-O-methylaniline （POT） were prepared by chemical oxidation method. The differences of two conducting polymers on structure and properties were studied by FT-IR and UV-vis. The results show that steric hinderance effect of methyl groups in the poly-o-methylaniline is more prominent than induction effect and hyperconjugation. Be due to the steric hinderance effect, molecular chains twist, the distance between molecular chains increases, and the transition of electric chargers in the molecular chains and interchains becomes difficult. Therefore, the conductivity of POT is less than that of PANI. In addition, compared with PANI, some absorption peaks of UV-Vis and FT-IR of POT move towards short wave resulting from the steric hinderance effect of methyl groups.