Evaluation of Polymer Nano Pigments Performance as Corrosion Inhibitor

Inherently conducting polymers (ICPs), including polyanilines, polythiophenes and polypyrroles areorganic materials that have electrical properties similar to inorganic materials such as semiconductors andmetals. ICPs have the potential to replace many of these materials due to lower manufacturing costs,lower density, better processability, higher mechanical flexibility and broader chemical functionalizationcapabilities. The starting materials to make polyaniline are the least expensive of all the inherentlyconducting polymers and polyaniline is the most thermally stable of the ICPs. The two most generalmethods used for synthesizing polyaniline are electrochemical and chemical oxidative polymerizations.Aniline, polyaniline and their derivatives including aniline black have all been considered for use incorrosion protection [1].Polyaniline blends (composite coatings) are usually considered to be the best choices for protectingmetals from corrosion. In these blends, polyaniline is highly dispersed in a classical polymer binder andcan provide many advantages [2].However, most of the organic coatings are permeable against the oxygen, water and chloride ionsthere are free volumes, cavities and defects inside the coating matrix generated during coating applicationor curing processes. Therefore, the mentioned corrosive species penetrate into the coating through themicroscopic electrolyte pathways. Therefore, obtaining a long corrosion protection using organic coatingswithout reinforcing it by other inhibiting materials seems impossible among them incorporation ofdifferent additives, inhibitors and anti corrosive pigments are found as the most effective methods.Nanopigments doped with inhibitive species like Zn, Ni, Co and Mn has been considered as route forobtaining inhibitive performance. These nanopigments release inhibitive species like Co2+, Mn2+ and Ni2+cations in the scratched area and protect it from corrosion through precipitating a passive film on the baremetal surface. The gole of this research is synthesized and characterization a novel anticorrosivenanopigment based on cobalt ferrite nanopigment and polyaniline - CoFe2O4 composite. The corrosioninhibition properties of the nanopigment was examined in the extract form in3.5 wt.% NaCl solution andafter inclusion into the epoxy coating by OCP analyze [3].

Keywords:

Corrosion Protection , Polymer Pigment