CASHEW NUT SHELL LIQUID (CNSL)
CNSL is a reddish brown viscous liquid extracted from a soft honeycomb structure inside the cashew nutshell and is a by-product of the Cashew industry.It is extracted from the cashew nut shell, which is a pericarp fluid of the Shell nut. CNSL is a mixture of four components: all are substituted phenols - anacardic acid (I), cardanol (II), cardol(III) and 2-methyl cardol(IV).
Anacardic Acid and Cardanol are monohydric phenols whereas Cardol and 2-methyl cardol are dihydric phenols. In the nut, CNSL occurs mainly as an anacardic acid (~90%) and cardol around slightly lower than 10%. The dual phenolic/alkenyl nature of CNSL makes it a potential natural raw material for the synthesis of water-resistant resins and polymers.