The Effectiveness of Cardanol as Plasticiser, Activator, and Antioxidant for Natural Rubber Processing

Cardanol is the main ingredient of cashew nut shell liquid (CNSL), an agro-byproduct. The merits of cardanol as plasticiser, activator, and antioxidant for natural rubber processing are compared with those of a conventional plasticiser (aromatic oil), coactivator (stearic acid), and antioxidants (styrenated phenol (SP) and trimethyl quinoline (TQ)). The cure characteristics, mechanical properties, extractability, and ageing behaviour are compared under identical conditions. It has been established that cardanol, when used as plasticiser, coactivator, or antioxidant, gives rise among other things to similar tensile properties, shorter cure times, and superior ageing behaviour when compared with the conventional plasticiser, coactivator, and antioxidants. This is of significance from the viewpoint of economy and conservation.