Manickam Jayakannan, Chennakkatu Krishna Sadasivan Pillai, Sundeep Kumar Dhawan, Dinesh Chandra Trivedi, Radhakrishnan Subramaniam
Conducting polymers based on renewable resource materials are very attractive because of their wide availability and lower cost compared to petroleum based products. Here we developed a novel dopant for electrically conducting polyaniline from renewable resource cardanol, the main component of cashew nut shell liquid (CNSL). The novel dopant 2-ω-unsaturated-4-hydroxy-4′-sulfinic acid azo benzene or otherwise known as cardanol azo sulfonic acid (1) is synthesized by reaction of diazotized sulphanilic acid (4-aminophenylsulfonicacid) with cardanol under the basic condition. The new cardanol azo sulfonic acid (1) has a long alkyl chains at the 2 positions, which increases the solubility of the dopant as well as polyaniline doped materials in common solvents for many applications. The present invention essentially comprises of three steps; (a) synthesis of cardanol azo sulfonic acid dopant 1 from cardanol (b) synthesis of electrically conducting polyaniline using 1 as dopant both doping the polyaniline emeraldine base in solution and melt and in-situ polymerization of aniline in presence of 1 in various organic and aqueous combination in the interfacial, emulsion and dispersion routes (c) preparation of polyaniline/dopant 1/thermoplastics blends in solution and melt process and controlling the particle size while maintaining the good morphology. The dopant (1) consisting polyaniline emeraldine salt and its thermoplastic blends are potential materials for various applications in opto-electronic industry.