Chloroprene vs. NBR

Attribute	Chloroprene	NBR
Chemical Formula	CH2=CCl-CH=CH2	(C4H6)x
Synonyms	Neoprene	Nitrile rubber
Common Uses	Wetsuits, gaskets, hoses	Seals, O-rings, gloves
Elasticity	Good	Excellent
Chemical Resistance	Good	Excellent
Temperature Range	-40°C to 121°C	-40°C to 120°C
Oil Resistance	Good	Excellent
Abrasion Resistance	Good	Excellent

Introduction

Chloroprene and NBR (Nitrile Butadiene Rubber) are two widely used synthetic rubbers with distinct properties and applications. Understanding the attributes of each material is crucial for selecting the appropriate rubber for specific applications. In this article, we will compare the key characteristics of Chloroprene and NBR, including their chemical structure, physical properties, resistance to various factors, and common applications.

Chemical Structure

Chloroprene, also known as polychloroprene or Neoprene, is a synthetic rubber derived from the polymerization of chloroprene monomers. It consists of repeating units of chloroprene, which is a chlorinated derivative of 1,3-butadiene. The presence of chlorine atoms in the polymer chain enhances its resistance to heat, ozone, and chemicals.

NBR, on the other hand, is a copolymer of butadiene and acrylonitrile. The acrylonitrile content in NBR can vary, resulting in different grades of NBR with varying properties. The higher the acrylonitrile content, the better the resistance to oil, fuel, and chemicals, but the lower the flexibility and low-temperature performance.

Physical Properties

Chloroprene exhibits excellent resistance to weathering, ozone, and aging, making it suitable for outdoor applications. It has good mechanical properties, including high tensile strength, elongation, and tear resistance. Chloroprene also maintains its flexibility over a wide temperature range, from -40°C to 120°C (-40°F to 248°F).

NBR, on the other hand, offers superior resistance to oils, fuels, and chemicals, making it a popular choice for applications involving contact with petroleum-based fluids. It has good mechanical properties, including high tensile strength and abrasion resistance. NBR also maintains its flexibility over a wide temperature range, from -30°C to 120°C (-22°F to 248°F).

Resistance to Factors

Chloroprene exhibits excellent resistance to flame, ozone, weathering, and aging. It is also resistant to oils, greases, and many chemicals, although it may not be suitable for applications involving strong acids, ketones, and esters. Chloroprene has good electrical insulation properties and is often used in electrical cables, gaskets, seals, and protective clothing.

NBR, on the other hand, offers excellent resistance to oils, fuels, and chemicals, including many acids, alkalis, and solvents. It is not recommended for applications involving exposure to ozone, sunlight, or strong oxidizing agents. NBR is commonly used in automotive seals, gaskets, hoses, O-rings, and oil-resistant gloves.

Common Applications

Chloroprene finds extensive use in various industries. Its excellent weathering resistance makes it suitable for outdoor applications such as roofing membranes, weatherstripping, and inflatable structures. Chloroprene's resistance to oils and chemicals also makes it ideal for automotive hoses, belts, and seals. Additionally, it is used in the manufacturing of wetsuits, gloves, and protective clothing due to its flame resistance and flexibility.

NBR is widely used in industries where resistance to oils, fuels, and chemicals is critical. It is commonly employed in automotive and aerospace applications, including fuel hoses, seals, gaskets, and O-rings. NBR's resistance to oil and fuel also makes it suitable for oil and gas exploration equipment, hydraulic systems, and industrial machinery. Additionally, NBR is used in the production of gloves, footwear, and seals for food processing and pharmaceutical industries.

Conclusion

Chloroprene and NBR are both versatile synthetic rubbers with distinct properties and applications. Chloroprene offers excellent weathering resistance, flexibility, and resistance to flame, while NBR excels in its resistance to oils, fuels, and chemicals. The choice between Chloroprene and NBR depends on the specific requirements of the application, such as exposure to environmental factors, contact with fluids, and desired mechanical properties. By understanding the attributes of each material, engineers and manufacturers can make informed decisions to select the most suitable rubber for their intended applications.