Synthesis and Characterization of some Diazotised Resins from Renewable Resource

Abstract

Cashew phenol, popularly known as Cardanol, is reddish brown liquid prepared from cashew nut shell liquid (CNSL). Cardanol is found to be an important renewable resource and possess unique phenolic group having a 15-carbon aliphatic side chain at meta position with varying degrees of unsaturation. It is immiscible in water but miscible in most of the organic solvents. It's excellent solubility in number of common organic solvents makes it an ideal choice for a large number of surface-coating applications including paints and primers, varnishes and lacquers, etc. The synthesis of resins involves diazotization of p-nitroaniline followed by coupling the diazotized product with cardanol in order to get diazotised p-nitroaniline cardanol dye. The condensation reaction between the resulting dye and furfural in presence of H2SO4 furnished the homopolymer resin. The homopolymer resin is further condensed with urea and thiourea in order to get the desired copolymer resin. All the steps are preceded with good yields and required simple purifications. The products from each step are characterized using Ultra violet-Visible spectroscopy, Fourier Transform-Infrared spectroscopy and 1H-Nuclear Magnetic Resonance spectroscopy. The expected product formation is confirmed by careful analysis of the spectral results and also compared with the previous literature reports. Further, the synthesized product will be subjected to Inter-penetrating polymer network sheet formation and checked its potential applications in the field of coating materials.