Polyisobutene
Polyisobutene is a widely used ingredient in cosmetics, personal care, and skincare formulations. Depending on its function, it may serve as a moisturizer, preservative, emulsifier, or active ingredient to enhance the overall effectiveness and performance of a product.
Polyisobutene (polyisobutylene) is a class of organic polymers prepared by polymerization of isobutene. The polymers often have the formula Me3C[CH2CMe2]nH (Me = CH3). They are typically colorless gummy solids.
 | |
 Sample of polyisobutene with a molecular weight of ~1,000,000
| |
| Names | |
|---|---|
| Other names
Polyisobutylene; Poly(isobutene); Poly(isobutylene); PIB
| |
| Identifiers | |
| ChEBI | |
| ECHA InfoCard | 100.108.750 |
| UNII | |
CompTox Dashboard (EPA)
|
|
| Properties | |
| (C4H8)n | |
| Molar mass | Variable |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
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 oligomers with Mns of about 500, is used as plasticizers. Medium and high MW polyisobutenes, with Mn ≥ 20,000, are components of commercial adhesives.
