Recent Trends of Cashew Nutshell Liquid: Extraction, Chemistry, and Applications

Abstract

The current concern about the use of unfriendly and poorly biodegradable chemicals has led to several research activities within the academic and industrial sectors. Studies on the use of cashew nutshell liquid (CNSL) as a source of raw material for diverse chemical industry applications are well documented. The liquid is extracted from the nutshell and can be further purified to several chemical constituents such as anacardic acid, cardanol, cardol, and 2-methyl cardol. The composition of CNSL varies depending on the mode of extraction, thus, it is necessary that researchers interested in this resource as starting material for their reactions be fully knowledgeable of the methods of extraction. The unique chemical structural features of these components offer the opportunity for different chemical modifications (thanks to various recent catalytic approaches) to suit various applications. CNSL and its derivative constituents have recently continued to find applications in various important fields including UV filters, pharmaceutical drugs, polymers, nanomaterials, corrosion inhibitors, detergents, insect repellants, and many others. This chapter, therefore, reports recent developments emanating from cashew nut usage.