Carboxylated Nitrile, or XNBR, is produced by adding a carboxylic acid side group to nitrile rubber, thereby adding more crosslinking sites than traditional NBR. As a result, solvent swell and abrasion resistance are significantly improved, as well as modulus, tensile strength and tear resistance. However, XNBRs give a higher hardness (up to 12 to 16 durometer points in most recipes) than comparable non-carboxylated NBRs, so care must be taken during the compounding and mixing stages in order to achieve the desired hardness. Water resistance, resilience and some low temperature properties are somewhat diminished.
|Low temperature flexibility||•|
|Dilute acids and bases||•|
|Petroleum oils and fuels||•|
-30 to 250 °F
*Excellent, good, fair and poor are intended to serve as general guidelines only. Actual testing in the application environment is always recommended.