THE EFFECT OF FILLERS ON SULPHENAMIDE AND THIOUREA CURE OF POLYACRYLIC RUBBER IN THE PRESENCE OF METAL-OXIDE

The effects of filler on the cyclohexyl benzothiazyl sulphenamide (CBS ) and ethylene thiourea (ETU) cure of polyacrylic rubber (ACM) in the presence of metal oxide (PbO) have been studied with a view to find ou t efficient fillers and their reinforcement mechanism. Carbon black (S RF N770), precipitated calcium carbonate and precipitated silica have been used individually and in combinations as fillers. In the case of the CBS accelerated system the reinforcement follows the trend carbon black > CaCO3 > silica. However, silica exhibits the highest reinforce ment in the system containing ETU as an accelerator and methylene dian iline (MDA) as a coagent. No synergistic effect has been observed in t he system having mixed fillers.