Nitrile Butadiene Rubber

Nitrile Butadiene Rubber (NBR), also known as Nitrile Rubber, is a synthetic rubber copolymer made from butadiene and acrylonitrile. This copolymerization process results in a polymer with excellent oil resistance, high resilience, and good mechanical properties.

Characteristics

1. Composition:
   • Acrylonitrile Content: Varies from 18% to 50%. Higher acrylonitrile content improves oil and fuel resistance but can reduce flexibility.
   • Butadiene Content: Provides elasticity and flexibility.
2. Physical Properties:
   • Mooney Viscosity: Typically 40-100 Mooney units, affecting processability and ease of mixing.
   • Tensile Strength: Generally high, contributing to durability and mechanical performance.
   • Elongation at Break: Ranges from high to moderate, depending on formulation and acrylonitrile content.
   • Hardness: Typically Shore A 40-90, allowing adjustment for different applications.
3. Durability:
   • Oil and Fuel Resistance: Excellent, crucial for applications involving petroleum products.
   • Heat Resistance: Good, capable of withstanding typical operational temperatures.
   • Chemical Resistance: Good against many chemicals, but less effective against strong acids and oxidizers.
   • Abrasion Resistance: Good, providing durability in high-wear environments.

Key Characteristics of Different NBR Types

1. Low Acrylonitrile Content (18-30%):
   • Characteristics: More flexible and elastic with lower oil resistance.
   • Applications: Suitable for general-purpose seals, gaskets, and hoses where high flexibility is needed but oil resistance is less critical.
2. Medium Acrylonitrile Content (30-40%):
   • Characteristics: Balanced properties with moderate oil and fuel resistance and good flexibility.
   • Applications: Commonly used in automotive gaskets, seals, and hoses where a balance between flexibility and resistance is required.
3. High Acrylonitrile Content (40-50%):
   • Characteristics: Excellent oil and fuel resistance but reduced flexibility and elongation.
   • Applications: Ideal for fuel hoses, O-rings, and seals in the automotive and aerospace industries where maximum oil resistance is crucial.

Applications

1. Automotive Industry:
   • Fuel Hoses: NBR with high acrylonitrile content resists fuels and oils.
   • Gaskets and Seals: Used in engines and transmission systems for effective sealing.
   • O-Rings: Found in various automotive components exposed to fuels and oils.
2. Industrial Applications:
   • Hoses: Used in transferring oils, fuels, and chemicals; high acrylonitrile content variants are preferred.
   • Gaskets and Seals: Employed in machinery where oil resistance is essential.
   • Belts: Applied in industrial belts that need resistance to oils and abrasion.
3. Oil and Gas Sector:
   • Drilling Equipment: Components such as seals and gaskets that require resistance to petroleum products.
   • Flexible Hoses: Used in the transfer of oil and gas.
4. Medical and Food Processing:
   • Medical Devices: Specialized formulations are used in certain medical equipment where oil resistance is needed.
   • Food Processing: NBR used in food-grade applications where resistance to oils is important, though it must be specifically formulated for food contact.
5. Consumer Products:
   • Household Items: Gaskets and seals in items that may come into contact with oils or chemicals.
6. Agricultural Machinery:
   • Equipment Components: For parts exposed to fuels and oils in agricultural machinery.

NBR's versatility in formulation allows it to be customized for a wide range of applications, offering excellent performance in environments where oil, fuel, and chemical resistance are critical.