SELF-VULCANIZABLE TERNARY RUBBER BLEND BASED ON EPOXIDIZED NATURAL-RUBBER, CARBOXYLATED NITRILE RUBBER AND POLYCHLOROPRENE RUBBER .2. EFFECT OF BLEND RATIO AND FILLERS ON PROPERTIES

Mill-mixed blends of epoxidized natural rubber (ENR), carboxylated nitrile rubber (XNBR) and neoprene form a self-vulcanizable ternary blend system which can be reinforced by fillers such as carbon black and silica. The effect of fillers on processing characteristics and physical properties of self-vulcanizable blends is similar to that of conventional rubbers. The properties depend on blend ratio and type of filler. The blend in the gum state shows poor failure properties like gum ENR, but shows high resilience and low compression set. Abrasion loss and heat build-up properties of the blend are nearer to those of gum neoprene vulcanizate. The filled blends show lower heat build-up due to non-uniform distribution of fillers in the miscible ternary blend. Mooney viscosity and Mooney scorch time of the blend are found to be intermediate between the control mixes of ENR and XNBR, but the Monsanto rheometric torque values are closer to ENR.