Butyl rubber (IIR), also called isobutylene-isoprene rubber, a synthetic rubber produced by copolymerizing isobutylene with small amounts of isoprene. Valued for its chemical inertness, impermeability to gases, and weather ability, butyl rubber is employed in the inner linings of automobile tires and in other specialty applications.

1. Butyl Rubber
Presented By:
Kishan Jamatia (16BPE048)
Tarun Parikh (16BPE075)
Savan Sardhara (16BPE110)
Vishal Rathod (16BPE169)

2. Preparation/ Synthesis
 Produced by cationic copolymerization between ≈ 98% isobutylene & ≈2%
isoprene
Typical Method:
 Initiator: Friedel- Craft acids(e.g. AlCl3)
 Medium: methyl chloride (reaction diluent) & boiling liquid ethylene
 Temperature: controlled at low temperature(-90 to -100 ℃)

3. Preparation/ Synthesis
Alternative Method:
 Initiator: Mixture of a major amount of diethylaluminium chloride & a minor
amount of ethylaluminium dichloride (activated by minute amounts of water/
methylalumino {MAO})
 Modified initiators: higher molecular weights, higher degrees of conversion &
higher isoprene contents in butyl rubber
 Medium: hexane
 Temperature: -60℃
 Activation by MAO allow higher polymerization temperature which does not require
much heat removal from reaction mixture

4. Properties of Butyl Rubber
 Low permeability to air, gases and moisture
 Vibration damping
 Low glass transition temperature
 Low modulus elastomer
 Low compression set
 Resistance to aging and to weathering from
atmospheric exposure
 Processing safety
 High Extensibility
 Blood Compatible
 Wide vulcanization versatility
 Fast cure rates

5. Uses of Butyl Rubber
 Tires
 Automotive
 Industrial
 Construction
 Adhesives
 Consumer products
 Bets sealant of all the known rubbers
 Blood compatible

6. Thank you