What is Nitrile Butadiene Rubber (NBR)
Nitrile Butadiene Rubber (NBR), also known as Buna-N, is a type of synthetic rubber that is a copolymer made from the polymerization of acrylonitrile and butadiene monomers. NBR is renowned for its excellent oil resistance, especially against alkanes, and possesses several advantageous properties such as high wear resistance, good airtightness, relatively good heat resistance, strong adhesion, and good aging resistance. However, it does have some limitations, including poor low-temperature flexibility, poor ozone resistance, poor insulation properties, and slightly lower elasticity, making it unsuitable for use as insulating material.
Chemical and physical properties
NBR can stretch up to 300% of its original length and has a tensile strength greater than 10N/mm^2. This rubber is highly resistant to mineral oils, vegetable oils, benzene, gasoline, and common dilute acids and alkalis. However, it is important to note that NBR's lip seals should not be used in conditions exceeding 80°C (176°F), as its stability against solvents decreases at higher temperatures. This characteristic underscores the need for careful selection of NBR for specific applications, particularly in environments where high temperatures or exposure to aggressive chemicals are common.
Chemical Resistance Chart
» Meaning of symbol:
OK: Recommended. △: Must confirm if usable by testing in advanced. X: Not recommended.
» This chart only provides the result of a single chemical to material, if a client uses more than one kind of chemical at the same time, please choose material by experience.
» This chart is for reference only which is not applicable to all working environments. Please refer to design equipment according to practical experience.
Category |
Name |
NBR |
Organic acids
|
Acetic acid
|
N/A |
Acetic acid, glacial
|
X
|
Acetic anhydride
|
X
|
Citric acid
|
△
|
Organic compound
|
Acetaldehyde
|
X
|
Acetone
|
X
|
Methyl alcohol
|
N/A |
Aniline
|
X
|
Benzaldehyde
|
X
|
Benzene
|
X
|
Benzyl alcohol
|
X
|
Benzyl chloride
|
X
|
Corn oil
|
N/A |
Ethanol
|
△
|
Ethylene glycol
|
OK
|
Fatty acid
|
N/A |
Formaldehyde
|
△
|
Formic acid
|
X
|
Hexane
|
N/A
|
Lactic acid
|
N/A
|
Methanol
|
OK
|
Paraffin oil
|
N/A |
Petroleum
|
N/A |
Phenol
|
X
|
Propane, liq
|
OK
|
Propanol
|
N/A
|
Stearic acid
|
X
|
Tannic acid
|
X
|
Tartaric acid
|
X
|
Toluene
|
X
|
Urea
|
N/A |
Inorganic compound
|
Ammonia
|
△ (gas)
X (water)
|
Ammonium chloride
|
△
|
Ammonium hydroxide
|
N/A |
Ammonium nitrate
|
N/A |
Ammonium sulfate
|
N/A |
Aqua regia
|
X
|
Barium chloride
|
N/A |
Barium hydroxide
|
N/A |
Brine
|
N/A |
Calcium Chloride
|
N/A |
Calcium hydroxide
|
N/A |
Carbonic acid
|
OK
|
Chloric acid
|
N/A |
Chloric |
X |
Chlorine
|
N/A |
Detergent
|
N/A |
Hydrobromic acid
|
OK
|
Hydrochloric acid
|
X (37%)
|
Hydrofluoric acid
|
N/A |
Hydrogen peroxide
|
X
|
Nitric acid
|
X
|
Phosphoric acid
|
X
|
Potassium hydroxide
|
X
|
Potassium nitrate
|
N/A |
Potassium sulfate
|
N/A |
Sodium carbonate
|
N/A |
Sodium hydroxide
|
X (aq)
|
Sodium nitrate
|
N/A |
Sulfuric acid
|
X (fuming)
|
Sulfur dioxide
|
X
|