Thermal stability of butyl/EPDM rubber blend vulcanizates

Butyl rubber has some disadvantages such as marginal green strength and only fair heat and ozone resistance. These disadvantages can generally be overcome by the partial replacement of butyl rubber (IIR) with ethylene propylene diene monomer rubber (EPDM). EPDM has a highly saturated backbone which gives it excellent resistance to the effect of oxygen and ozone. However, IIR has some unsaturation due to the isoprene units in its structure. In this investigation, data and observations on the heat resistance behaviour of IIR/EPDM blend vulcanizates over a range of compositions and temperatures are highlighted. The results show that blending of IIR with EPDM is beneficial because of the enhancement of heat resistance of the blend vulcanizates.