HNBR (Highly Saturated Nitrile)

Hydrogenated nitrile rubber is a synthetic polymer that has been saturated with hydrocarbon chains in nitrile rubber by hydrogenation. This special hydrogenation process reduces many of the double bonds in the NBR polymer backbone, resulting in higher heat, ozone, chemical and mechanical resistance than nitrile rubber.

Like NBR, different HNBR polymers contain different amounts of acrylonitrile (ACN). ACN content can range from 17% to 49%. Lower ACN content provides better low temperature performance, but poorer resistance to fuel oils and polar lubricants. Higher ACN content improves resistance to fuel oils and polar lubricants, but results in poorer low temperature performance.

Standard HNBR typically has 36% ACN content

Highly saturated HNBR, high temperature resistance up to +175°C

Temperature range

General grade: -40 ~ 150℃ (TR10-22 ~ -24℃)

Low temperature grade: -55 ~ 150℃ (TR10-35 ~ -39℃)

High temperature type: -30℃ ~ +175℃

Hardness range

Shaw A55 degrees to 90 degrees

Color

Black, green, blue, brown, brownish red, grey, or customer-specified colors

Application

HNBR is widely used in the automotive and refrigeration industries. Due to the need for ecological and environmental protection, the old refrigerant R22 is gradually being replaced by new refrigerants. In the past, chloroprene rubber seals were usually used, but in new refrigerants such as R134A, R410a and R407c, hydrogenated nitrile rubber is also widely used.

Usually HNBR is added with internal lubrication to improve the convenience of installation or reduce friction in dynamics.

For contact with food or beverages, HNBR can be formulated with "white list" ingredients specified in FDA 21.CFR 177.2600.

HNBR is commonly used in automotive air conditioning systems, where R134a refrigerant or new environmentally friendly refrigerants such as R401a, R404a, R410a, R507 and new environmentally friendly refrigerant R744 are used. In R744 air conditioning systems, it requires excellent resistance to CO2 explosive decompression at high pressure and high temperature.

HNBR also has good wear resistance, so it is also widely used in automotive axle systems.

In deeper oil wells, thermal recovery, crude oil, hydrogen sulfide, steam and explosive decompression are more demanding. The material needs to have better resistance, and special compounds of HNBR can be used for this.