Investigation on natural cashew nut shell liquid based imprinted polymers
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The objective of this work was to use monomers from cashew (Anacordium Accidentalel) nut shells to develop molelarly imprinted polymers. Cashew nut shell liquid (CNSL) is a cheap and renewable agro byproduct consisting of versalite monomers. Solvent-extracted CNSL contains over 80% anaeardic acid (AnAcr) with more than 90% degree of unsaturation in its C15 side chain. In this study, isolation of AnAc from natural CNSL was achieved via calcium anacardate procedure and through continuous supercritical carbon dioxide (seCO2) extraction. From AnAc monomer, anacardanyI acrylate (AnAcr) and anacardanyL methacrylate (AnMcr) monomers were synthesized and their chemical structures were characterized by Fourier transform IR and NMR. Different imprinted bulk polymers based on AnAc, AnAncr and AnMcr functional monomers have been prepared. Each functional monomers was separately co- polymerized in toluene with ethylene glycol dimethacry and divinybenzene as cross-linkers, using racemic propranolol as a model template. While the AnAc based polymer revealed a meager rebinding ability, the imprinted polymers made from AnMcr displayed highly specific propranolol binding. At a polymer concentration of 2mg/ml, AnAcr and AnMcr based imprinted polymers were able to bind over 50% of race propranolol (initial concentration 1.2nM). under the same condition propranolol uptake by the two non-imprinted control polymers was less than 20%, chiral recognition properties of these polymers were further confirmed using tritium-labeled (s) propranolol as a tracer in displacement experiments suggesting that the apparent affinity of the imprinted chiral sites for the correct enantiomer is at least 10 times that of the mismatched (R ) propranolol. Cross reactivity studies of these polymeter showed that the (S) –propranolol and (R) –timolol. Moreover, the presence of the aliphatic side chain in AnMcr resulted in more uniform imprinted beads. Therefore, these results denote an important advancement towards exploiting renewable source from cashew nut shells to synthesize valuable new polymer product.