New HNBR Compounds to Meet Stringent High Temperature and Media Resistance

Wednesday, October 12, 2016: 4:15 PM
Rm 304-5 (David L. Lawrence Convention Center )
Daryl Meyer1, Ulrich Frenzel2, Susanna Lieber2, Sarah David3, Karola Schneiders3 and Hiyam Salem3, (1)Arlanxeo Corp., Pittsburgh, PA, (2)Arlanxeo Deutschland GmbH, Cologne, Germany, (3)Arlanxeo Deutschland GmbH, Dormagen, Germany
Advances towards more sustainable automotive technology created challenges for the necessary rubber parts used in seals and hoses. The chemically very aggressive bio-diesels for example have forced to developed HNBR compounds which can resist oxidative aging in fluids and ensure safe and leak-free operation.
Automotive coolant technologies have evolved towards longer lasting and environmentally friendlier coolant fluids. Coolants using the so-called organic acid technology (OAT) such as G13 have caused high swell and loss of properties of HNBR compounds under prolonged immersion times and high temperatures. Subsequent research has shown that glycol and organic acids lead to the formation of esters and oxidation products which are preferentially absorbed by HNBR rubber parts. By varying the amount and type of carbon black the volume swell could be largely reduced. To further improve the mechanical properties, both after hot air aging and in G13-based coolant a new mineral based filler was introduced. With vinyl-silane as coupling agent finally an optimized Therban® compound was designed, which meets the stringent requirements of an actual automotive specification In complex fluids like coolants the rubber part should be seen as a composite which required both the optimization of the rubber net and the incorporated filler system