一个综合化学实验——聚苯胺的合成

A Comprehensive Chemical Experiment——Synthesis of Polyaniline

聚苯胺由于具有独特的电学、光学、良好的稳定性、低成本、易于制备和应用范围广泛等特性引起了人们的广泛关注。聚苯胺可以通过化学氧化聚合和电化学聚合来制备。本实验旨在为学生提供一种快速、实用的制备聚苯胺导电聚合物的方法,展示其广泛应用。化学氧化聚合是一种具有合成简单、快速实用、原材料成本低等优点并可以用于制备大规模的聚苯胺的方法。苯胺的化学氧化聚合是在强酸性溶液中进行的,通过添加一种氧化剂过硫酸铵引发,聚合成掺杂的聚苯胺。聚合的特征是在缓慢的诱导期间颜色变化,然后在聚合阶段由于放热反应的自加速特性使得温度突然升高。掺杂后的PANI易通过与碱反应脱掺杂成为翠绿亚胺碱,其为蓝色且不导电,翠绿亚胺碱形式的PANI可与质子酸反应被掺杂重新成为翠绿亚胺盐使其具有呈现绿色并导电,从而扩展聚苯胺的应用范围。

Polyaniline has attracted wide attention due to its unique electrical,optical,good stability,low cost,easy preparation and wide range of applications.Polyaniline can be prepared by chemical oxidation polymerization and electrochemical polymerization.The aim of this experiment is to provide students with a fast and practical method for preparing polyaniline conducting polymers and to demonstrate its wide application.Chemical oxidation polymerization is a kind of simple synthesis,fast and practical,low cost of raw materials and can be used to prepare large-scale polyaniline.The chemical oxidation polymerization of aniline is carried out in a strong acidic solution by adding an oxidant ammonium persulfate,which polymerization into doped polyaniline.Polymerization is characterized by color changes during slow induction followed by a sudden increase in temperature during the polymerization stage due to the self-accelerating nature of the exothermic reaction.The doped PANI is easy to be dedoped by reacting with alkali to become emerald imine base,which is blue and non-conductive.The emerald imine base form of PANI can react with proton acid and be doped to become emerald imine salt again,which makes it green and conductive,thus expanding the application range of polyaniline.