Hydrogenated Nitrile Butadiene Rubber (XNBR)
XNBR is a nitrile rubber (NBR) with the addition of a carboxyl group to saturate the butadiene segment of the carbon polymer backbone. The added carboxyl group greatly improves the resistance of NBR to abrasive and tear wear without affecting its oil and solvent resistance or its thermal stability. For this reason, XNBR based parts are usually applied in dynamic assembly such as seals and rod wipers.
XNBR is found in:
High abrasion resistance shoes
Rice dehusking rolls
Oil extraction industry artifacts
Standard Compound: -20°C (-4°F) to 100°C (212°F)
Special Compound (High temp): 125°C (257°F)
Hardness: 50 to 90 Shore A
ASTM D1418 Designation: XNBR
ASTM D2000 Designation: BG, BK, CH
Standard Colors: Black
XNBR is produced by a crosslinking of carboxylated nitrile rubber with a standard preparation by a sulfur recipe, or in some cases metal oxides/peroxides.
XNBR performs well in aliphatic hydrocarbon, vegetable/mineral oil, greases, diesel, water, dilute acids, alkali, and salt solutions.
XNBR rubber compounds are susceptive to aromatic hydrocarbons, chlorinated hydrocarbons, ketones, acetic acids, ethylene esters, strong acids, and brake fluids with a glycol base.