Butyl refers to a class of synthetic rubbers made by polymerizing isobutylene, known for their excellent impermeability, flexibility, and chemical resistance.
Butyl rubber is a synthetic elastomer widely used in commercial and industrial applications where airtightness, chemical resistance, and durability are essential. Produced from isobutylene with a small amount of isoprene for cross-linking, butyl rubber provides unique properties not found in natural rubber. It is highly resistant to gas and moisture penetration, making it ideal for sealing and insulating environments. In wire and cable manufacturing, butyl is often applied as insulation or jacketing material, particularly in medium- and high-voltage applications. Its dielectric strength protects conductors from electrical breakdown, while its flexibility and resistance to ozone, heat, and environmental stress ensure reliable performance. Beyond electrical uses, butyl rubber is also common in gaskets, adhesives, protective linings, and industrial equipment components.
Butyl rubber used in cables is typically evaluated under UL (Underwriters Laboratories), IEC (International Electrotechnical Commission), and ASTM (American Society for Testing and Materials) standards for insulation, safety, and compliance.
Butyl rubber was developed in the 1930s by researchers at Standard Oil Company of New Jersey, later ExxonMobil. It was created as a synthetic alternative to natural rubber with improved impermeability and durability. Since then, butyl has become a key material in industries requiring long-lasting sealing, insulation, and protective qualities.