HNBR and EVM for Long Lasting High Performance Applications in Cars

摘要

As more than 50 % of all elastomers end directly or indirectly in all kinds of cars the demands and requirements of that industry certainly do influence the way elastomers are being developed these days. Researchers at Bayer had seen 25 years ago that the work horse for the car industry, the oil resistant Acrylonitrile-Butadiene-Rubber NBR, would no longer be able to withstand the required conditions. They developed therefore the hydrogenated NBR Therban~R which showed a significant increase in heat resistance up to 150℃. HNBR is obtained by selective hydrogenation of NBR leading to a polymer with controllable saturation of the backbone and still intact pendant nitrile groups which are responsible for the oil resistance (Picture 3). Sulfur cure can be used with HNBR polymers having still 2 - 5 % residual unsaturation in the backbone giving finished product with a hot air aging resistance of up to 140℃ (Zn peroxide - S-cure system).