How good is the oil resistance of the nitrile rubber gasket?

The oil resistance of the nitrile rubber gasket is very good. It is one of the rubber materials with the most outstanding oil resistance performance. The following provides a detailed analysis from aspects such as the oil resistance principle, performance, and application scenarios:

1. Oil-resistant principle

Nitrile rubber (NBR) is a synthetic rubber formed by the copolymerization of acrylonitrile (ACN) and butadiene. Its molecular structure contains strong polar cyano groups (-CN). The cyano groups can interact with the polar groups in oil molecules, forming a stable adsorption layer, thereby effectively preventing the penetration and swelling of oil molecules into the rubber. This property makes Nitrile rubber highly resistant to non-polar or weakly polar oils (such as mineral oil, fuel oil, lubricating oil, etc.).

2. Performance

Excellent oil resistance: The volume expansion rate of nitrile rubber in petroleum-based oils is low, and its physical properties change little, enabling it to maintain its mechanical strength and elasticity for a long time.

The oil resistance increases with the increase of acrylonitrile content: The higher the acrylonitrile content, the greater the cyano group density, and the better the oil resistance. However, at the same time, the low-temperature performance will correspondingly decrease.

The oil resistance is superior to that of other general-purpose rubbers: Compared with natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), etc., nitrile rubber has more outstanding oil resistance, second only to fluororubber (FKM) and polysulfide rubber and other special rubbers.

3. Application scenarios

The oil resistance of nitrile rubber enables it to be widely used in the following fields:

Automotive industry: Used for manufacturing oil pipes, oil seals, O-rings, gaskets, etc., which are oil-resistant components.

Petrochemical industry: Used for manufacturing oil-resistant hoses, valve seals, oil tank linings, etc.

Aerospace industry: Used for manufacturing seals for fuel systems and hydraulic systems.

Industrial equipment: Used for manufacturing oil-resistant bearings, gears, conveyor belts, etc.

4. Limitations

Although nitrile rubber has excellent oil resistance, it still has limitations in certain specific environments:

Poor resistance to polar solvents: In polar solvents such as ketones, esters, and aromatic hydrocarbons, the durability of nitrile rubber will significantly decrease.

Limited high-temperature performance: The long-term use temperature of ordinary nitrile rubber does not exceed 120℃. Its performance may decline in high-temperature oils.

Poor low-temperature performance: As the acrylonitrile content increases, the low-temperature performance of nitrile rubber will deteriorate, and the brittle temperature may reach below -20℃.

FOREVER SEALS! Seals manufacturer, accept custom seals, from design to research and development, from production to testing, a full range of services. For more information, please contact FOREVER SEALS directly. FOREVER SEALS product experts are here to help you! Whatsapp: +86-18098184099；WeChat: +86-13049188460；  E-mail: sales@foreverseals.com.