Studies on the Use of Cardanol as Plasticizer for Silica-Filled Nitrile Rubber

Cardanol is the main ingredient of cashew nut shell liquid (CNSL), an agro-byproduct. Its comparative merits for plasticizing silica-filled nitrile rubber (NBR) is the subject of this paper. Esters like dioctyl phthalate (DOP), polyesters, polyester ethers, polyester polyethers, etc are the conventional plasticizers employed for such compounding requirements. In this study, the mechanical properties, ageing behavior and torque time curves during cure of NBR plasticized by both these materials are compared under identical conditions. It has been established that cardanol when used as plasticizer, gives rise to similar mechanical properties, cure times and superior thermal stability in NBR vulcanizates.