Butyl rubber (BR) is blended with polypropylene (PP) in ratios of 92: 8, 84: 16, 68: 32, 50: 50, 32: 68, 16: 84, and 8 : 92 (w/w) for the study of dynamic vulcanization. It is observed that the cure torque increases with the decrease in BR content up to the ratio of 50: 50. No cure torque is observed in the ratios of 16: 84 and 8: 92 of BR: PP blends as the PP content becomes very high. On comparison of cure rate of the blends, the BR (100%) shows the highest cure rate because of the fast saturation of double bonds present in BR, whereas maximum cure torque, work energy, and totalized torque are observed in the 32: 68 BR: PP blend. It is the result of the formation of an interpenetrating network.