Polyisobutene

 ( Organic Polymers ) 

Polyisobutene ( polyisobutylene) is a class of organic polymers prepared by polymerization of isobutene. The polymers often have the formula Me₃CCH₂CMe_2nH (Me = CH₃). They are typically colorless gummy solids.

Cationic polymerization, initiated with a strong Brønsted or Lewis acid, is the typical method for its production. The molecular weight (MW) of the resulting polymer determines the applications. Low MW polyisobutene, a mixture of with M_ns of about 500, is used as . Medium and high MW polyisobutenes, with M_n ≥ 20,000, are components of commercial .

• Butyl rubber
• Polybutene