Overview on Post-Polymerization Functionalization of Butyl Rubber and Properties

Butyl and halobutyl rubber (IIR and HIIR) is an important class of polymeric materials with great potential applications in diverse areas like manufacturing of tires, tubes, adhesives, sealants, pharmaceutical closure, flexible electronics, etc. The IIR and HIIR having exceptional air impermeability, superior oxidative stability, high chemical stability, and better damping properties are attracting significant research attention in improving these products to explore new applications. These properties of IIR and HIIR can be tailored by the introduction of functional moieties via a copolymerization or postpolymerization modification process. The highly sensitive cationic polymerization process can restrict the functionalization with most of the monomers via the copolymerization method. Hence the functionalization of IIR and HIIR can only be carried out using postpolymerization modification methods and those play a crucial role in tailoring the properties of IIR and HIIR. This review summarizes the development of new classes of functionalized IIR and HIIR via the postpolymerization modification method. The improved properties and new applications of the modified IIR and HIIR have been discussed.