Comb-block copolymers of isobutylene copolymer backbone with functional polymer comb arms

An elastomeric nanocomposite composition comprising

• (a) a comb-block copolymer comprising (i) a polymeric backbone comprising at least one halogenated copolymer comprising units derived from isoolefins having from 4 to 7 carbons and a para-alkylstyrene and (ii) one or more polymeric comb arms comprising at least one functional polymer, wherein the functional polymer comprises units derived from a vinyl terminated C6 to C20 aromatic;
• (b) at least one halogenated elastomer component comprising units derived from isoolefins having from 4 to 7 carbons;
• and
• (c) at least one nanofiller, wherein the nanofiller is selected from the group consisting of graphene, chemically converted graphene, graphite, expanded graphite, carbon black, and mixtures thereof.

A method for producing a comb-block copolymer, the method comprising:

• polymerizing one or more monomer components comprising units derived from at least one of acrylates, acrylamides, and acrylonitrile using a halogenated copolymer initiator having a benzylic-halide moiety via atom transfer radical polymerization (ATRP),
• wherein the halogenated copolymer initiator comprises units derived from isoolefins having from 4 to 7 carbons and a para-alkylstyrene;
• and
• wherein the polymerization is performed in the presence of a transition metal complex catalyst at a temperature ranging from 30° C. to 150° C.