Bromobutyl Rubber

often abbreviated as BIIR (Brominated Isobutylene-Isoprene Rubber), is a synthetic rubber that is a modified version of butyl rubber. It is created by introducing bromine atoms into the butyl rubber polymer structure. This modification enhances the reactivity of the material and provides improved vulcanization properties. Here are some key characteristics and common uses of bromobutyl rubber.

Key Characteristics:

Vulcanization Properties:

Bromobutyl rubber has better vulcanization properties compared to standard butyl rubber. Vulcanization is the process of cross-linking rubber molecules to improve its strength, elasticity, and other mechanical properties.

Gas Impermeability:

Like butyl rubber, bromobutyl rubber retains excellent impermeability to gases. It is often used in applications requiring airtight seals or barriers.

Chemical Resistance:

It offers good resistance to a wide range of chemicals, acids, and bases, making it suitable for applications in contact with corrosive substances.

Weather Resistance:

Bromobutyl rubber exhibits good resistance to weathering, UV radiation, and ozone, making it suitable for outdoor applications.


It remains flexible at low temperatures, which is important for applications in cold environments.

Common Uses
of Bromobutyl Rubber:

Pharmaceutical Stoppers
Sealants and Gaskets
Vibration Dampers
Bromobutyl rubber is valued for its combination of vulcanization properties, gas impermeability, chemical resistance, and flexibility. It is particularly well-suited for applications where enhanced vulcanization is needed, such as pharmaceutical stoppers and certain tire components.