CNSL oxyacetic derivatives, new bio-based binders for paint preparation

Abstract

The global coating industry produces tens of millions of metric tonnes of paints each year, and this quantity continues to grow. Most of these paints are obtained totally or partially from fossil resources, and many of them still use volatile organic compounds (VOCs) and/or other harmful chemicals. This paper describes the use of the cashew nutshell liquid (CNSL) as a raw material for synthesis of paint binders (sustainable materials). These binders are obtained in a single chemical step without tedious separation. These new bio-based materials (renewable resources) form stable films (green coatings) in a short drying time. The formulated paints are 100% aqueous, have low toxicity and ecotoxicity and require no additional drying agents or VOCs. Oxidative coupling of the alkylidene chain and addition of carboxylic acid to the carbon–carbon double bonds are implemented. The products obtained can be applied on different kinds of surfaces, such as glass slides, metal, wood or concrete, and exhibit good stability against various solvents and tropical conditions.