Provided herein are methods for preparing a functionalized polyolefin from an unsaturated polyolefin containing one or more non-aromatic main-chain double bonds and for reducing the size and/or polydispersity index (i.e., increasing the homogeneity) of the unsaturated polyolefin.

Provided herein are methods for preparing a functionalized polyolefin from an unsaturated polyolefin containing one or more non-aromatic main-chain double bonds and for reducing the size and/or polydispersity index (i.e., increasing the homogeneity) of the unsaturated polyolefin.

The invention relates to an efficient polymerization process and its use to produce novel copolymers with a specific microstructure. In particular, the invention relates to butyl rubbers with novel microstructure, preferably those obtainable by copolymerization of monomer mixtures comprising isobutylene and isoprene in diluents comprising 2,3,3,3-tetrafluoro-1-propene. In a further aspect the invention relates to halogenated copolymers obtainable from such novel copolymers by halogenation.

The invention relates to an efficient polymerization process and its use to produce novel copolymers with a specific microstructure. In particular, the invention relates to butyl rubbers with novel microstructure, preferably those obtainable by copolymerization of monomer mixtures comprising isobutylene and isoprene in diluents comprising 2,3,3,3-tetrafluoro-1-propene. In a further aspect the invention relates to halogenated copolymers obtainable from such novel copolymers by halogenation.