ASTM D 1418 Designation: CR

ASTM D 2000, SAE J200 Type / Class: BC, BE

STANDARD COLOR: Black

TRADE NAMES:
• Baypren® (Bayer Corp.)
• Neoprene® (DuPont Dow Elastomers)

RELATIVE COST: Medium

GENERAL TEMPERATURE RANGE: -40° to +250° F

Chemically known as polychloroprene but often referred to by the trade name Neoprene®, chloroprene was one of the first synthetic materials developed as an oil-resistant substitute for natural rubber. Neoprene’s molecular structure closely mirrors that of natural rubber, with the exception that a chlorine atom has replaced a methyl (CH3) sidegroup (see Figure 33). Presence of a chlorine atom in each repeating unit increases the compound’s polarity and improves its resistance to hydrocarbon fluids despite the presence of a double bond in the main chain. Because the chlorine atom essentially deactivates the double bond, chloroprene is more resistant to oxygen, ozone, and UV light than similarly unsaturated polymers.

Due to the similarity of their structures, natural rubber and chloroprene are generally comparable in their good strength, abrasion resistance, resilience, elongation, and strain crystallization characteristics. Both also offer a similar low fatigue property, low heat build up, low temperature flexibility, and high bondability. Chloroprene surpasses natural rubber in its resistance to aging, heat, oils, ozone, and solvents. Chloroprene has also gained FDA approval for use in the food and beverage industries.

CR PERFORMS WELL IN:
• High aniline point petroleum oils
• Mild acids
• Refrigeration seals (resistance to Freon® & ammonia)
• Silicone oil & grease
• Water

CR DOES NOT PERFORM WELL IN:
• Hydrocarbons (aromatic, chlorinated, nitro)
• Ketones (MEK, acetone)
• Phosphate ester fluids
• Strong oxidizing acids

MATERIAL PROFILES MAIN PAGE