Abstract: Disclosed herein is a method for reducing dripping in flaming polystyrene compositions which method comprises incorporating into the polymer composition an effective amount of a polychloroprene rubber component in order to reduce dripping of the flaming composition.

Abstract: Disclosed herein is a method for preparing fire retardant styrenic polymer molding compositions with improved impact strength which compositions contain a metal oxide and a halogenated fire retardant additive. The method comprises dispersing the metal oxide into a minor portion of the styrene polymer component using high intensity mixing and temperatures at or above the fusion temperature of the styrene polymer in order to obtain a uniform dispersion. The metal oxide-polystyrene dispersion is then blended with the other ingredients of the polyblend. The resulting blend is compounded at temperatures greater than 255.degree. C. and then comminuted to form a molding composition.

Abstract: This invention relates to an improved process for producing polyblends wherein said process has unexpectedly high rates of polymerization wherein a polymerizable mixture of a monovinylidene aromatic monomer and a diene rubber are partially polymerized en masse through phase inversion with the partially polymerized mixture being suspended in an inert liquid and the polymerization essentially completed; the improvement comprising utilizing a particular catalyst system, in combination with, a saturated aliphatic acid containing 12 to 20 carbon atoms and a compound selected from the group consisting of hydrated salts and water in the mass and suspension polymerization steps of the process. Said catalyst system having a half life of less than one hour at 130.degree. C., and a 10 hour half life at a temperature of 95.degree. to 115.degree. C.