Rubber modified styrenic polymer compositions formed from hydroperoxide derivatives of rubbery polymers

Claim 1

A rubber modified polymeric composition the composition comprising: (a) a generally rigid matrix phase of a homopolymer of a monovinylidene aromatic monomer or an interpolymer of a monovinylidene aromatic monomer and one or more monomers copolymerizable therewith; and (b) a rubber modifying grafted rubbery copolymer said grafted rubbery copolymer being formed by a process, the steps of the process comprising: (1) forming a polymerizable mixture comprising one or more free-radically polymerizable monomers; (2) dissolving a rubbery polymer having allylic hydrogen in the polymerizable mixture to form a rubber-containing polymerizable solution; (3) adding to the rubber-containing polymerizable solution, a photosensitizing amount of a photosensitizing agent; (4) oxygenating the rubber-containing polymerizable solution; (5) exposing the oxygenated rubber-containing polymerizable solution to electromagnetic radiation wherein triplet oxygen is converted to singlet oxygen, and an average of from about 0.5 to about 4 hydroperoxide derivatives of the rubbery polymers are formed on each rubbery polymer chain; (6) initiating polymerization of the rubber-containing polymerizable solution; and (7) continuing polymerization of the rubber-containing polymerizable solution at least until the desired degree of grafting to the rubbery polymer is obtained; wherein the rubber-modified polymeric composition has a rubbery polymer content of from about 2 to about 30 weight percent based on total composition weight.