Polyisobutene (polyisobutylene) is a class of organic polymers prepared by polymerization of isobutene. The polymers often have the formula Me 3 C [CH 2 CMe 2] n H (Me = CH 3). They are typically colorless gummy solids. Cationic polymerization, initiated with a strong Brønsted or Lewis acid, is the typical method for its production.