NBR (Nitrile Butadiene Rubber): The Workhorse Elastomer

NBR (Nitrile Butadiene Rubber) is a synthetic rubber material that offers excellent resistance to certain oils, fuels, and chemicals. It is widely used in the automotive, industrial, and aerospace industries due to its excellent mechanical properties and resistance to abrasion and tearing. In this blog, we will take a closer look at NBR and its various applications. This material has many common names, including NBR, Nitrile, Buna, and Buna-N. In this blog, we will primarily refer to it as NBR.

What is NBR?

NBR is the term used to describe a copolymer of acrylonitrile and butadiene. The amount of acrylonitrile used in the copolymer varies between compounds and has a profound effect on the mechanical and physical properties of the material. Generally, NBR is very oil-resistant, has strong mechanical properties, is resistant to wear, and is relatively inexpensive. The acrylonitrile content in NBR can range from 18% to 50%, with higher levels of acrylonitrile providing increased resistance to oils and chemicals. These properties make NBR the most commonly used general purpose molded O-ring material. Canyon Components carries a huge variety of NBR based seals and supplies thousands of customers in a diverse range of industries.

Specific physical and chemical resistances vary by compound formulation. Basic NBR is not resistant to weathering or ozone without special formulation. Hydrogenated versions of NBR (HNBR) are more resistant to temperature, chemicals, and ozone. If you would like to learn more, check out our NBR page.

How Does NBR Work?

NBR offers excellent resistance to certain oils, fuels, and chemicals due to the presence of nitrile groups in its polymer structure. The material is also highly resistant to abrasion and tearing, making it a popular choice for use in industrial applications.

NBR has good tensile strength, elongation, and compression set, making it an ideal material for manufacturing seals, gaskets, O-rings, and other components that require excellent mechanical properties and chemical resistance.

Features of NBR

NBR has a number of benefits that cause it to be an extremely popular commodity material.

1. Relative low cost.
2. Good resistance to compression set and tear/abrasion.
3. Good resistance to many petroleum oils/greases, hydraulic fluids, alcohol, ambient water, silicone greases, mineral oil and grease.
4. Good resistance to many fuels and aliphatic hydrocarbons (propane, butane, diesel fuel, fuel oils) as well as ethylene-glycol based fluids.
5. Compatible with HFA, HFB and HFC fluids.
6. Available in multiple compounds to meet performance and cost requirements.

Limitations of NBR

NBR is still a commodity material, however, and has limitations.

1. Not compatible with ozone, direct sunlight, UV, or weathering.
2. Poor resistance to aromatic fuels, glycol-based brake fluids, polar solvents, non-flammable hydraulic fluids (HFD), aromatic/chlorinated hydrocarbons, and strong acids.
3. 15 year shelf life Service temperature range (varies with application).
4. Typically -20°F to 200°F (-30°C to 100°C). *Special formulations allow a range of -65°F to 275°F (-54°C to 135°C).

Applications of NBR

NBR has a broad range of applications across various industries, including:

1. Automotive Industry: NBR is widely used in the automotive industry for manufacturing fuel hoses, O-rings, oil seals, gaskets, and other components that require resistance to oils and fuels.
2. Industrial Industry: NBR is used in the industrial industry for manufacturing seals, gaskets, O-rings, and other components that require resistance to oils, fuels, and chemicals.
3. Aerospace Industry: NBR is used in the aerospace industry for manufacturing seals, O-rings, gaskets, and other components that require resistance to oils, fuels, and hydraulic fluids.
4. Medical Industry: NBR is used in the medical industry for manufacturing gloves, catheters, and other medical equipment that requires resistance to oils and chemicals.
5. Consumer Goods Industry: NBR is used in the consumer goods industry for manufacturing products such as footwear, sporting goods, and hoses that require resistance to oils and fuels.

Conclusion

NBR is a highly versatile synthetic rubber material that offers excellent mechanical properties and resistance to oils, fuels, and chemicals. Its wide range of applications makes it a popular choice for use in the automotive, industrial, aerospace, medical, and consumer goods industries. If you require a material that offers excellent resistance to oils, fuels, and chemicals for your industrial application, NBR may be an excellent choice for you.

Where can I get NBR parts?

With the request a quote page, you can get directly in contact with our team of specialists who will help get you the parts you need.

Sources:

[1] Fazli, A., & Rodrigue, D. (2020). Waste Rubber Recycling: A review on the evolution and properties of thermoplastic elastomers. Materials, 13(3), 782. https://doi.org/10.3390/ma13030782

[2] Sedlačík, M. (2021). Advances in elastomers. Materials, 14(2), 348. https://doi.org/10.3390/ma14020348

[3] Rahman, M. M., Oßwald, K., Reincke, K., & Langer, B. (2020). Influence of Bio-Based Plasticizers on the properties of NBR materials. Materials, 13(9), 2095. https://doi.org/10.3390/ma13092095