Hi Laleh,

Hydrogenated nitrile rubber (HNBR ) is made by selective hydrogenation of the NBR butadiene rubbers which improves the temperature and ozone resistance considerably. Nitril Butadiene Rubber (NBR) is a synthetic rubber copolymer of acrylonitriles (ACN) and butadienes. Good Luck

Salim Y Hanna

Hi Salim

Thank you for your answer. I need its compound composition.

HNBR (hydrogenated nitrile rubber) polymers are high temperature and oil resistant elastomers. HNBR compounds are formulated to meet demanding applications and environments with a wide operational temperature range. They can be produced in presence of hydrogen gas and precious metals at designated temperature and pressure.

Hi Laleh,

Structure of hydrogentated nitrile-butadiene-rubber :

-[( CH2CH2CH2CH2)n-(CH2CH(CN))m]-

Maryam Abdolrahmani I want to use this compound for sealing purpose and it needs low compression set. How can I obtain a final product with compression set

Here is a brief answer, based on some quick searches and my prior background in this area.. Nitrile rubber, also known as NBR or acrylonitrile-butadiene rubber, is a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene. Trade names include Perbunan, Nipol, Krynac, Buna-N, and Europrene.

HNBR is made via selective hydrogenation of the NBR butadiene groups in the Nitrile rubbers, which improves the temperature and ozone resistance considerably. Due to the polymer structure, HNBR offers both resistance to polar and nonpolar media. ... HNBR offers extraordinarily good mechanical properties and abrasion resistance.

Here is some more technical information from a website of a sealing solutions company, Trellborg Sealing (https://www.tss.trelleborg.com/global/en/industries/automotive_4/capabilities_5/materials_6/hydrogenated_nitrile_butadiene_rubber__hnbr_/hydrogenatednitrilebutadienerubberhnbr.html):

HNBR is made via selective hydrogenation of the NBR butadiene groups which improves the temperature and ozone resistance considerably. Due to the polymer structure, HNBR offers both resistance to polar and nonpolar media. The selection for dedicated automotive applications depends on the ACN content which can range from 18% to 50% (this influences the swelling in oil), as well as on the degree of saturation (this influences the heat resistance). HNBR offers extraordinarily good mechanical properties and abrasion resistance. The operating temperature ranges, when in contact with mineral oils and greases from -30°C/-22°F to 140°C/284°F and for a short period of time up to +160°C/320°F. Special types can be used down to -40°C/-40°F.

The material has:

Superior heat resistance up to 140°C

Superior environmental resistance

Improved resistance to polar fluids

Applications:

Due to the good abrasion resistance and oil resistance, the main applications are actuator seals for gear box applications. In addition, HNBR is often used in air conditioning applications..

Thanks.

Hi Laleh,

Cure system based on peroxide will give a better compression set performance for HNBR. Post curing temperature and duration also plays an important role in the final compression set. Some of the studies shows that post curing at 150°C for 8 -10 hrs can give an optimum compressions et performance.

Thanks

Hi Lale,

based on my experience, I think that using CB fillers between 60-70 phr will give you better compression set performance.

also using peroxide curing agents more than 4 or 5 phr may help you to achive your proper properties.

good luck