Abstract: Impact resistant compositions are prepared by the incorporation of acrylic rubber particles (or multi-stage emulsion polymer particles containing a rubbery layer) in a predominantly methyl methacrylate matrix. The emulsion particles are prepared in water as a latex stabilized with anionic groups. The particles are transferred to a methyl methacrylate medium by destabilizing the latex with a quaternary ammonium salt and optionally a di- or multivalent inorganic salt. Impact resistant compositions are prepared by separating the water from the methyl methacrylate layer and polymerizing the methyl methacrylate.

Abstract: Impact resistant compositions are prepared by the incorporation of acrylic rubber particles (or multi-stage emulsion polymer particles containing a rubbery layer) in a predominantly methyl methacrylate matrix. The emulsion particles are prepared in water as a latex stabilized with anionic groups. The particles are transferred to a methyl methacrylate medium by destabilizing the latex with a quaternary ammonium salt and optionally a di- or multivalent inorganic salt. Impact resistant compositions are prepared by separating the water from the methyl methacrylate layer and polymerizing the methyl methacrylate.

Abstract: Particle size, swelling, and other characteristics of unsaturated polyester beads are controlled in a suspension polymerization system to make beads suitable for use as fillers in molding and forming. Process steps include degassing prior to polymerization, positive pressure during polymerization, and washing to remove suspending agent.

Abstract: A clear, cast acrylic sheet of improved impact strength may be prepared by dispersing or dissolving 8-14% of an ABA block copolymer, (where A is styrene, B is a hydrogenated butadiene, containing a large 1-2 butadiene fraction) in a methyl methacrylate casting mixture which contains 0.1- 20% styrene, and polymerizing in sheet form by heating with free-radical initiators.

Abstract: Styrene is copolymerized with maleic anhydride by mixing maleic anhydride with styrene under mass polymerization conditions in a ratio of styrene to maleic anhydride of at least 5:1, continuing to add maleic anhydride throughout a mass polymerization stage until about 25% to about 40% of the styrene monomer is reacted to produce a reaction mass in which the polymerized maleic anhydride is about 1% to about 10% of the total reaction mass. The polymerization is then completed in a pH-adjusted free-radical initiated suspension stage, which generates homopolymer of styrene. During the suspension stage about 10% to about 20% of the bound maleic anhydride is hydrolyzed. The acid component of the bound maleic acid may be converted back to the anhydride through the use of a vented extruder.

Abstract: Crystal polystyrene with improved flow properties useful in injection molding is prepared in a two-stage process in which a first portion of monomer is polymerized in the presence of about 0.3 to about 2.0% peroxide initiator to convert about 70 to 95% of the monomer present to polymer having a number average molecular weight of 20,000 to 50,000 and a weight average of 50,000 to 100,000; then adding the rest of the monomer thereby reducing the catalyst concentration to generate a second moiety of polymer so that the final product has a weight average molecular weight of 150,000-300,000, and a number average of 50,000-70,000.