High Performance TPU's based on Polycarbonate Soft Segments
|Date Published||June 1, 2004|
Polycarbonate soft segments provide an improved balance of oil resistance and resistance to hydrolytic type degradation. Ester type polyurethanes are often selected over ether types for hydraulic sealing applications because ester types are more resistant to oil swell. Ester types, however, are not resistant to chemical degradation by hydrolytic type mechanisms and often fail prematurely not just in hot humid environments but also in contact with acidic or alkaline additives and degradation products which may be found in some hydraulic fluids. The work presented herein compares 85-90 Shore A polycarbonate, polyether, and polyester type TPU seal compounds demonstrating a polycarbonate type TPU with low compression set, high strength, and an improved balance of oil resistance and hydrolytic stability.