Bromobutyl Rubber (BIIR) Advantages
1. Extremely low air & gas permeability
BIIR has one of the best airtight performances among all elastomers. Its gas permeability is only 1/7 of natural rubber, perfect for vacuum sealing, air pressure retention, and gas barrier applications.
2. Excellent ozone & weather aging resistance
BIIR resists ultraviolet rays, oxidation, and outdoor aging extremely well. It maintains stable performance under long-term sun exposure and harsh atmospheric environments, far better than NBR and natural rubber.
3. Good heat resistance
Continuous working temperature ranges from -40°C to 150°C. It offers higher thermal stability than standard butyl rubber and chlorobutyl rubber, with low aging degradation after long high-temperature operation.
4. Superior vibration damping & shock absorption
BIIR has excellent damping properties, effectively absorbing vibration and noise, widely used for mechanical shock pads and automotive damping parts.
5. High chemical purity & biocompatibility
Medical-grade BIIR is clean, non-toxic, and chemically stable. It is the standard material for pharmaceutical stoppers and medical sealing components.
6. Good vulcanization compatibility
Bromine active structure enables fast vulcanization and good co-curing compatibility with other rubber materials, easy for custom compounding and compression molding.
Bromobutyl Rubber (BIIR) Disadvantages
1. Poor oil and solvent resistance
BIIR swells easily in mineral oil, gasoline, hydrocarbon solvents. Not suitable for oil-sealing or fuel-contact working conditions.
2. Low mechanical wear resistance
Compared with PU and NBR, BIIR has weaker abrasion resistance and tensile strength, not suitable for high-friction dynamic sealing.
3. Poor acid and alkali resistance
Not recommended for long-term contact with strong acid, strong alkali, and corrosive chemical liquids.
4. Limited hardness range
BIIR is mainly soft and medium-soft elasticity, not suitable for high-hardness structural rubber parts.
Typical BIIR Rubber Applications
- Medical bottle stoppers, medical sterile sealing gaskets
- Tire inner liners, tire curing bladders
- Vacuum seals, airtight sealing parts
- Outdoor weatherproof rubber gaskets and strips
- Automotive vibration damping rubber pads
- Construction waterproof and airtight membrane components
- Custom compression molded BIIR rubber parts