Abstract: The present invention discloses a process for producing a core-shell polymer that comprises: (1) preparing a monomer solution which is comprised of (a) at least one monomer, optional one crosslinking monomer (b) a conjugate acid of a surfactant with a pKa of less than 14, and (c) a controlled free radical polymerization agent; (2) preparing an aqueous medium which is comprised of (a) water, and (b) a conjugate base of a weak acid wherein the pKb of the base is less than 14; and (3) mixing the monomer solution with the aqueous medium under conditions that result in the in-situ formation of an emulsifier to produce a polymerization medium, and (4) initiating free radical polymerization within the polymerization medium to produce a core polymer, wherein the core contains a free radical control agents, (5) adding a second monomer to the polymerization medium containing the core polymer, and (6) allowing polymerization to proceed in the presence of the free radical control agent to produce the core-shell polymer.

Abstract: A thermoplastic vulcanizate composition comprised of (a) thermoplastic resin selected from the group consisting of polyphenylene ether, polypropylene, polyethylene, and polystyrene, (b) at least one elastomer selected from the group consisting of butadiene-isoprene copolymer rubbers, copolymers of a conjugated diolefin monomer and an acrylate monomer, copolymers of a conjugated diolefin monomer and an methacrylate monomer, copolymers of a conjugated diolefin monomer and a vinyl aromatic monomer, copolymers of a conjugated diolefin monomer and an acrylonitrile monomer, blends of polyisoprene rubber with styrene-butadiene rubber, wherein the elastomer is at least partially crosslinked, wherein the repeat units in the elastomer are distributed throughout the elastomer in an essentially random manner, and (c) oil.