Abstract: A shell-and-tube heat exchanger, for removing volatile substances from a polymer solution by degasification, includes a bundle of tubes arranged vertically and parallel to each other in a shell chamber through which a fluid heat-transfer medium flows. The upper end of each tube is fixed in an upper tube sheet and the lower end of each tube is fixed in a lower tube sheet, and the polymer solution flows through the tubes in the direction of gravity. One feature is that a multilayer woven wire fabric is attached to the top of the upper tube sheet. The finest meshed layer of the fabric has a mesh width of 50 ?m to 1000 ?m. The invention also relates to a method for removing volatile substances from a polymer solution by degasification in a shell-and-tube heat exchanger and use of the shell-and-tube heat exchanger.

Abstract: The invention relates to a process for the preparation of thermoplastic molding materials comprising A) from 39 to 99% by weight of at least one thermoplastic polymer, B) from 1 to 60% by weight of a flameproofing component comprising B1) an expandable graphite, and C) from 0 to 60% by weight of further additives, the percentages by weight being based in each case on the total weight of the components A) to C) and together giving 100% by weight, by mixing melts of the components A), B) and, if present, C) in a screw extruder, the screw extruder comprising at least one metering zone, one plasticating zone, one homogenization zone and one discharge zone in this sequence along the conveying direction, wherein the metering of the expandable graphite B1) into the screw extruder is effected at a point behind which—viewed in the conveying direction—the extruder screw comprises substantially no shearing elements, and thermoplastic molding materials which can be prepared by these processes, the use of said the

Abstract: A shell-and-tube heat exchanger, for removing volatile substances from a polymer solution by degasification, includes a bundle of tubes arranged vertically and parallel to each other in a shell chamber through which a fluid heat-transfer medium flows. The upper end of each tube is fixed in an upper tube sheet and the lower end of each tube is fixed in a lower tube sheet, and the polymer solution flows through the tubes in the direction of gravity. One feature is that a multilayer woven wire fabric is attached to the top of the upper tube sheet. The finest meshed layer of the fabric has a mesh width of 50 ?m to 1000 ?m. The invention also relates to a method for removing volatile substances from a polymer solution by degasification in a shell-and-tube heat exchanger and use of the shell-and-tube heat exchanger.

Abstract: The invention relates to thermoplastic molding compositions comprising A) from 55 to 98% by weight of at least one vinylaromatic copolymer impact-modified with a particulate graft rubber, B) from 1 to 44% by weight of a flame retardant comprising B1) an expandable graphite, B2) a phosphorus-comprising flame-retardant compound, and B3) a fluorine-comprising polymer, C) from 1 to 20% by weight of a non-particulate rubber comprising polar groups, and D) from 0 to 40% by weight of further additives, where the percentages by weight are in each case based on the total weight of components A) to D) and give a total of 100% by weight, and also to processes for the preparation of these molding compositions, to the use of these molding compositions for the production of moldings, of fibers, of foams, or of foils, and also to the resultant moldings, fibers, foams, and foils.

Abstract: The invention relates to a process for the preparation of thermoplastic molding materials comprising A) from 39 to 99% by weight of at least one thermoplastic polymer, B) from 1 to 60% by weight of a flameproofing component comprising B1) an expandable graphite, and C) from 0 to 60% by weight of further additives, the percentages by weight being based in each case on the total weight of the components A) to C) and together giving 100% by weight, by mixing melts of the components A), B) and, if present, C) in a screw extruder, the screw extruder comprising at least one metering zone, one plasticating zone, one homogenization zone and one discharge zone in this sequence along the conveying direction, wherein the metering of the expandable graphite B1) into the screw extruder is effected at a point behind which—viewed in the conveying direction—the extruder screw comprises substantially no shearing elements, and thermoplastic molding materials which can be prepared by these processes, the use of said the

Abstract: Process for preparing rubber-containing thermoplastic molding compositions, by using polymerization to prepare at least one elastomeric polymer A and at least one thermoplastic polymer B, and mixing these with one another, the elastomeric polymer A being present in dispersed form in an aqueous phase after the polymerization, which comprises adding at least one pH-buffer system to the aqueous phase after the polymerization of component A has ended.

Abstract: Shear forces are used for essentially salt-free coagulation of plastics dispersions or rubber dispersions. For this, method of use is made of an apparatus with at least one shearing module which has a stator and a rotor arranged within the stator, where the surfaces facing toward one another in the stator and in the rotor are in each case smooth, or at least the rotor exhibits a structure formed on its surface and facing from this in the direction of the stator, and between the stator and the rotor there is a gap of predetermined gap width. The process is carried out by passing the dispersion to be coagulated through the gap between stator and rotor and precipitating the dispersion by rotation of the rotor with predetermined shear rate and shear deformation.

Abstract: A thermoplastic molding composition having little intrinsic color is produced from a graft copolymer and a thermoplastic polymer. The graft copolymer is produced from a soft elastomeric particulate graft base obtained by polymerization of a conjugated diene alone or with a small amount of a monoethylenically unsaturated monomer, upon which is grafted a vinylaromatic monomer and acrylonitrile and optionally another monoethylenically unsaturated monomer. The thermoplastic polymer is a copolymer of a vinylaromatic monomer and acrylonitrile and optionally an additional monoethylenically unsaturated monomer. The thermoplastic molding composition has a low level of intrinsic color coupled with good mechanical properties and can be processed by, for example, extrusion, injection molding, calendaring, blow molding, compression molding, or sintering.

Abstract: Process for the production of foam boards having a minimum thickness of 20 mm and a cross-sectional area of at least 50 cm.sup.2 by extruding a mixture of the styrene polymer, from 1 to 10% by weight, based on the styrene polymer, of a blowing agent, wherein the blowing agent contains at least one ether from the group consisting of dimethyl ether, methyl ethyl ether and methyl vinyl ether.