Polyisobutylene is a synthetic rubber made from the polymerization of isobutylene, a colorless gas. It is known for its excellent impermeability to gases and moisture, making it useful in various applications, including adhesives, sealants, and coatings. This versatile material is also used in the production of tire inner linings, where its durability and resistance to aging are beneficial. Additionally, polyisobutylene can be blended with other polymers to enhance their properties, contributing to its widespread use in industries such as automotive and construction.