Amine, polypyrrole, polythiophene, etc. Among them, polyaniline series is produced in large quantities and applied in many industries because of its outstanding conductive stability and low cost. However, in the process of synthesizing polyaniline, benzidine may exist, which limits the research of researchers, because benzidine is toxic and a carcinogen. Therefore, polypyrrole and polythiophene in aromatic compounds have become more potential conductive polymer systems. However, polypyrrole and polythiophene are insoluble and refractory, which brings great difficulties to processing. Therefore, researchers have carried out alkylation, alkoxylation or other substitution reactions on its main chain, thus developing a series of derivatives of polypyrrole and polythiophene.
In the late 1980s, scientists from Bayer Company in Germany first studied poly (3,4-ethylenedioxythiophene), a new thiophene derivative, which is often abbreviated as PEDOT in Eur. Patent 339340 (1988). The initial goal was to obtain antistatic coating materials with good environmental stability, but later research showed that this polymer not only had good environmental stability, but also had high conductivity, and had been commercialized in many aspects abroad.
Like conductive polypyrrole and conductive polyaniline, PEDOT can prepare cathode materials of solid electrolytic capacitors by chemical oxidation in-situ polymerization. Its conductivity is much higher than that of conductive polypyrrole and TCNQ composite salt.
Electrical conductivity. In high temperature and high humidity environment, the stability of PEDOT is better than that of polypyrrole.
In a word, PEDOT is superior to polypyrrole in environmental stability, electrical conductivity and moisture resistance. Therefore, it is very valuable to study the solid electrolytic capacitor with it as electrolyte.