An impressive emulsion polymerization route for the synthesis of highly soluble and conducting polyaniline salts

• Polyaniline salts were synthesized by a novel and an efficacious emulsion polymerization pathway.
• The salts are completely soluble in a large number and variety of organic solvents.
• The salts are electrically highly conducting.
• They provide extra ordinary resistance to the steel surfaces against harsh corrosive environment of the Oceans.

We report a sophisticated emulsion polymerization route for the synthesis of polyaniline (PANI) salts. In this process, the chemical oxidative polymerization of aniline was carried out in the presence of two dopants i.e., dodecylbenzenesulfonic acid (DBSA) and sulfuric acid (H2SO4). The synthesized PANI salts were highly soluble in a large number and variety of common organic solvents (so far highest number of solvents including the less hazardous ethanol) and showed very good conductance. Presumably the presence of DBSA and sulfuric acid moieties, respectively, contributed toward the improvement in solubility and conductance. After optimization of the reaction parameters, the obtained polymers were systematically characterized with cyclic voltammetry, in situ conductance, in situ UV–vis spectroelectrochemical and intrinsic viscosity measurements. X-ray diffraction, TGA and SEM were used for further analysis. The materials showed very good electrochemical and electrochromic reversibility and high thermal stability (up to 500 °C). Moreover, potentiodynamic measurements revealed that coatings of this polymer can provide extra ordinary resistance to the steel surfaces particularly against the harsh corrosive environment of the oceans.