Porous organic polymers from cashew nut shell liquid: Derived carbonized material for carbon dioxide capture

Abstract The fast developing world is in search of measures to control the accumulation of unused by‐products and waste materials generated during the production of useful commodities. Accordingly, wastes from agro‐industrial sectors can form raw materials for the production of various resources that are extensively used in many areas such as gas sorption and energy production. In the present work, cashew nut shell liquid (CNSL), the vesicant liquid present in the outer shell of cashew seed, forms the source material for the synthesis of porous organic polymers for carbon dioxide capture. Herein, novel types of hypercrosslinked polymers (HCPs) are synthesized via a simple Friedel–Crafts reaction with CNSL as the starting material. Polymerization of natural CNSL with dimethoxymethane/bis‐(chloromethyl)‐biphenyl as external crosslinker provides products in quantitative yield. One of the synthesized HCP is tuned to attain the required high porosity by carbonization at elevated temperatures using an activator. Thus, activated carbon material prepared at 700°C is found to have a high surface area of 880 m 2 /g with a good carbon dioxide adsorption capacity of 14.72 wt%. These porous materials had moderate isosteric heat of adsorption (23–31 kJ/mol) with excellent recycling capability.