USE OF POLYANILINE AND ITS DERIVATIVES IN CORROSION PROTECTION OF COPPER AND SILVER

This study examines the use of spin-applied conjugated polymers such a s polyanilines for corrosion and dissolution protection of silver and copper. In particular, attention is given to the protection that these polymers provide under conditions of an applied potential and at elev ated temperature. These particular conditions are those in which curre nt inhibitors such as benzotriazole do not provide acceptable protecti on for the metal. A number of polyaniline derivatives are studied, inc luding the unsubstituted parent polymer and the substituted poly-o-phe netidine both nondoped and doped, with several different protonic acid s. The polymers are readily soluble in organic solvents and can be app lied as thin coatings onto the metal surface. The corrosion protection of the resulting structure is determined by electrochemical and induc tively coupled plasma techniques using water as an electrolyte and und er varied conditions of temperature, humidity, and bias. It is found t hat polyaniline could either enhance the corrosion rate or produce sig nificant corrosion protection depending on the chemical nature of the polymer backbone and the conditions in which the material is processed and doped. The poly-o-phenetidine is found to adhere well to the meta l surface and provides exceptional protection both under an applied po tential and at elevated temperature.