Nitrile Rubber (NBR) has the best oil resistance, making it the ideal choice for a fuel transfer hose. The higher the acrylonitrile content, the better the resistance to oil and fuel. However, this may come at a cost; elasticity and compression resistance are adversely affected, and because of these effects, a compound with medium acrylonitrile content is often selected.
Nitrile rubber or NBR is a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene. The chemical name of nitrile synthetic rubber is acrylonitrile-butadiene copolymer. It is one of the important synthetic rubber types having a high resistance to aliphatic hydrocarbon oils and fuels.
The acrylonitrile content of nitrile sealing compounds varies considerably—from 18% to 50%—which influences the physical characteristics of the finished material.
There are different grades available with nitrile rubber manufacturers and suppliers. The higher the acrylonitrile (ACN) content in a grade of nitrile rubber, the higher will be the oil resistance but then the low temperature flexibility will get poorer.
Nitrile rubber has high resilience and high wear resistance. However, it has only moderate strength along with limited weathering resistance and poor aromatic oil resistance. Nitrile rubber can generally be used down to about -30C but special grades of NBR can work at lower temperatures too.
Nitrile Rubber belongs to the family of unsaturated copolymers of acrylonitrile and butadiene.The physical and chemical properties of nitrile rubber vary depending on the polymer’s composition of acrylonitrile.Different grades are available for this rubber. The higher the acrylonitrile content within the polymer, the higher the oil resistance.
NBR or the nitrile synthetic rubber is considered the workhorse of the rubber products of the automotive and other industrial units. By selecting an elastomer with the appropriate acrylonitrile content in balance with other properties, industrial nitrile rubber (NBR) is used in a wide variety of application areas requiring oil, fuel, and chemical resistance.
In the automotive area, NBR is used in water handling applications and in fuel and oil handling hose, seals and grommets. With a temperature range of –40 to +125 degree celcius, NBR materials can withstand all automotive applications. This form of synthetic rubber because of its resilience is the perfect material for disposable lab, cleaning, and examination gloves.
The industrial nitrile rubber is used for making variety of goods including:
NBR has decent mechanical properties when compared with other elastomers, and high wear resistance. However, NBR is not ozone or weather resistant and therefore not ideal as a hose cover.
NBR hose under category of HS Code 40093100.
Abbreviation NBR ASTM D-2000 Classification BF, BG, BK Chemical Definition Acrylonitrile Butadiene RRP Compound Number Category 30000 Series
♦Physical & Mechanical Properties Durometer or Hardness Range 20 – 95 Shore A Tensile Strength Range 200 – 3,500 PSI Elongation (Range %) 350 % – 650 % Abrasion Resistance Good to Excellent Adhesion to Metal Excellent Adhesion to Rigid Materials Good to Excellent Compression Set Good to Excellent Flex Cracking Resistance Fair to Good Impact Resistance Fair to Good Resilience / Rebound Good Tear Resistance Good to Excellent Vibration Dampening Fair to Good
♦ Chemical Resistance Acids, Dilute Good Acids, Concentrated Poor to Fair Acids, Organic (Dilute) Good Acids, Organic (Concentrated) Poor Acids, Inorganic Fair to Good
♦ Chemical Resistance Alcohol’s Fair to Good Aldehydes Poor to Fair Alkalies, Dilute Good Alkalies, Concentrated Poor to Good Amines Poor Animal & Vegetable Oils Good to Excellent Brake Fluids, Non-Petroleum Based Poor Diester Oils Fair to Good Esters, Alkyl Phosphate Poor Esters, Aryl Phosphate Poor to Fair Ethers Poor Fuel, Aliphatic Hydrocarbon Good to Excellent Fuel, Aromatic Hydrocarbon Fair to Good Fuel, Extended (Oxygenated) Fair to Good Halogenated Solvents Poor Hydrocarbon, Halogenated Poor to Fair Ketones Poor Lacquer Solvents Fair LP Gases & Fuel Oils Excellent Mineral Oils Excellent Oil Resistance Good to Excellent Petroleum Aromatic Good Petroleum Non-Aromatic Excellent Refrigerant Ammonia Good Refrigerant Halofluorocarbons R-11, R-12, R-13 Refrigerant Halofluorocarbons w/ Oil R-11, R-12 Silicone Oil Good Solvent Resistance Good to Excellent
♦ Thermal Properties Low Temperature Range - 70º F to 0º F Minimum for Continuous Use (Static) - 40º F Brittle Point - 70° F to 0º F High Temperature Range + 210° F to + 250º F Maximum for Continuous Use (Static) + 250º F
♦ Environmental Performance Colorability Excellent Flame Resistance Poor Gas Permeability Fair to Excellent Odor Good Ozone Resistance Fair to Good Oxidation Resistance Good Radiation Resistance Fair to Good Steam Resistance Fair to Good Sunlight Resistance Poor to Good Taste Retention Fair to Good Weather Resistance Fair to Good Water Resistance Good to Excellent