HNBR

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HNBR is the abbreviation for hydrogenated acrylonitrile butadiene rubber , which is mainly used for toothed belts in motor vehicles.

properties

The chemical properties of HNBR are comparable to those of NBR ( nitrile rubber ). Due to the lack of double bonds in comparison to NBR, HNBR is considerably less reactive. The difference lies in the significantly higher temperature resistance of approx. 150 ° C (continuous use) instead of just 100 ° C for NBR. The weather resistance is also improved (oxidation, ozone, UV resistance). HNBR is resistant to mineral oils, ozone and acid gases.

Fully hydrogenated HNBR types are crosslinked with peroxides. In the case of partially hydrogenated types, crosslinking with sulfur is also possible. The latter shows poor ozone and temperature resistance. The advantage of the partially hydrogenated types is improved low-temperature flexibility and a higher degree of crosslinking, which is reflected in a lower compression set.

application areas

The main area of ​​application for HNBR is timing belts in motor vehicles. It is also used for O-rings when high chemical and thermal resistance is required.