Abstract: Thermoplastic molding materials based on styrene polymers which have been made impact-resistant and on polyphenylene ethers, wherein the particles of the soft component of the styrene polymer which has been made impact-resistant have a mean diameter of more than 1 micron, and wherein the proportion of particles which have a diameter of less than 0.6 micron is not less than 40% by weight and the proportion of particles which have a diameter of from 0.6 to 3 microns is less than 3% by weight.

Abstract: Thermoplastic molding materials which contain a copolymer which has been made impact-resistant with a rubber. The copolymer is produced by polymerizing a mixture of a monovinyl-aromatic compound and an acrylic acid derivative or methacrylic acid derivative in the presence of a rubber. The folding materials contain a specific proportion of soft component. The diameter of the particles of the soft component, and the swelling index of the soft component, lie within a specific range, and the tensile strength of the molding material is higher than the yield strength.

Abstract: A process for the manufacture of high impact and translucent polystyrene, in which, in a first stage, styrene is prepolymerized in mass or in solution in the presence of a rubber, and the polymerization is then completed in mass, in solution or in aqueous suspension. The prepolymerization is taken to a stage where the amount of styrene converted is from 3 to 10 times the amount of the elastomer constituent of the rubber, and at this conversion the disperse soft-component phase formed should have a mean particle size of less than 1 .mu.m and should contain from 35 to 65% by weight of free or chemically bonded polystyrene segments. The translucent styrene polymers of high impact strength may be used for packaging purposes.

Abstract: Thermoplastic molding compositions, based on polymers of a monovinyl-aromatic compound which have been modified with rubber to increase their impact strength, which also exhibit increased stress crack resistance.The increased stress crack resistance is achieved if the proportion of the soft component in the polymer which has been modified to increase its impact strength, and the particle size and swelling index of the soft component phase, conform to particular values, and the tensile strength and yield stress of the thermoplastic molding compositions bear a particular ratio to one another.The molding compositions may in particular be used for the manufacture of internal liners of refrigerators and foodstuff packaging containers.

Abstract: A process for admixing additives to plastics and simultaneously removing volatile constituents in a horizontal devolatilizing extruder. Taken in sequence in the direction of flow, the additives are first introduced into the devolatilizing extruder from above, and the plastic melt, solution or dispersion is then introduced from below, while the bulk of the volatile constituents are withdrawn from the devolatilizing extruder at an orifice located vertically above the point at which the plastic is fed in. The process permits the removal of volatile constituents with simultaneous admixture of additives during aftertreatment of plastics, in a single step and at very high throughputs.

Abstract: Acrylonitrile or monomer mixtures containing acrylonitrile are purified by treating them with alkaline reacting compounds followed by distillation. The products are particularly suitable for the manufacture of acrylonitrile polymers showing improved color stability.

Abstract: A continuous process for the polymerisation of olefinically unsaturated monomers in bulk or in solution in which at least a portion of the low-viscosity materials to be fed to the polymerization zone is thoroughly mixed with a portion of the high-viscosity contents of the polymerization zone in a mixing zone disposed upstream of the polymerization zone, which mixture is then continuously fed to the polymerization zone. The resulting polymers have a uniform composition and a narrow molecular weight distribution. They may be converted to shaped articles by thermoplastic methods.