Polyisobutylene

Polyisobutylene (also known as PIB) is a synthetic rubber, or elastomer. It is a polymer of isobutylene, a hydrocarbon. Polyisobutylene is used in a variety of applications, including adhesives, sealants, and lubricants.

Chemical Structure

Polyisobutylene is a polymer of isobutylene, which is a four-carbon hydrocarbon. The polymerization process involves the use of a catalyst, typically a strong acid such as sulfuric acid or aluminum chloride. The resulting polymer has a highly regular structure, with all of the isobutylene units oriented in the same direction. This gives polyisobutylene its unique properties, including its high resistance to heat, chemicals, and oxidation.

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Chemical structure of polyisobutylene

Properties

Polyisobutylene is a highly versatile material with a number of desirable properties. It is resistant to heat, chemicals, and oxidation, making it suitable for use in a wide range of environments. It is also highly flexible and has excellent gas barrier properties, which makes it useful in applications such as tire inner liners and fuel hoses.

Applications

Polyisobutylene is used in a wide range of applications, including:

• Adhesives and Sealants: Polyisobutylene is used in the manufacture of adhesives and sealants due to its excellent adhesion properties and resistance to heat and chemicals.

• Lubricants: Polyisobutylene is used as a viscosity modifier in lubricants. It improves the performance of the lubricant by increasing its viscosity and reducing its tendency to thin out at high temperatures.

• Medical Applications: Polyisobutylene is used in some medical applications due to its biocompatibility and resistance to oxidation. It is used in the manufacture of medical devices such as catheters and in pharmaceutical formulations.

Health and Safety

Polyisobutylene is generally considered to be safe for use in many applications. However, like all chemicals, it should be handled with care. Exposure to polyisobutylene can cause irritation to the skin and eyes. Ingestion or inhalation can cause gastrointestinal or respiratory irritation.

See Also

• Isobutylene
• Polymerization
• Synthetic rubber
• Elastomer