Abstract: The invention relates to expanded polypropylene beads having a density of from 5 to 200 g/l and a bead diameter of from 1 to 10 mm which comprise from 0.002 to 20% by weight of graphite particles.

Abstract: In a process for preparing expandable polymer beads based on a mixture made from A. a biodegradable aliphatic/aromatic copolyester and B. a biodegradable naturally occurring polymer, the mixture A+B is melted in an extruder, mixed with a volatile organic blowing agent, extruded and pelletized.

Abstract: The invention relates to a process for the drying of coagulated water-containing rubber particles. These are treated with an aqueous solution of any desired substances in monodisperse solution in water in such a way that, at least for some period, the surface of the rubber particles is completely covered by the aqueous solution. It is preferable to use an aqueous solution of substances selected from the group consisting of salts, alcohols, acids and sugars. This method can reduce the internal water content between the particles resulting from coagulation, without major usage of energy or time.

Abstract: Open-cell moldable foams are based on a thermoplastic matrix which comprises A. from 99 to 50% by weight of a styrene polymer and B. from 1 to 50% by weight of a polymer of low compatibility with the styrene polymer.

Abstract: In a process for preparing expanded or expandable polymer beads based on biodegradable saturated polyesters made from at least one diol and from at least one dicarboxylic acid, A. polymer pellets are dispersed in a liquid, B. a volatile blowing agent is injected into the dispersion and made to impregnate the pellets at an elevated temperature, C. the pressure on the dispersion is reduced at an elevated temperature, whereupon the pellets comprising blowing agent expand to give foam, and, respectively, D. the pellets are isolated from the liquid.

Abstract: A process for preparing expandable particulate styrene polymers wherein from 5 to 50% by weight of expanded graphite and also, if desired, from 2 to 20% by weight of a phosphorus compound, are present as flame retardants, by suspension polymerization of styrene in the presence of the flame retardants.

Abstract: Flame-retardant foam slabs are based on styrene polymers wherein from 1 to 12% by weight of expanded graphite and also, if desired, from 1 to 12% by weight of a phosphorus compound are present as flame retardants.

Abstract: The invention relates to expandable polystyrene beads which comprise graphite particles with an average particle size of more than 50 &mgr;m, and also to a process for their preparation by free-radical polymerization of styrene in aqueous suspension. The graphite particles, suspended in styrene, are added to the polymerization mixture at a conversion of from 10 to 100%.

Abstract: The invention relates to a process for preparing styrene polymers which comprise water as sole blowing agent, by polymerizing styrene in aqueous suspension in the presence of from 0.1 to 15% by weight of a solid substance insoluble in water and in styrene, for example carbon black or graphite.

Abstract: The invention relates to a process for the preparation of expandable able styrene polymers containing particles of graphite by polymerization merization of styrene in aqueous suspension in the presence of particles of graphite having a mass density of less than 1.8 g/cm3.

Abstract: Expandable styrene polymers containing graphite particles are prepared by polymerizing styrene in aqueous suspension in the presence of graphite particles and of two peroxides which decompose at different temperatures, by a process in which the peroxide decomposing at the lower temperature forms neither benzoyl nor benzyl radicals on decomposition.

Abstract: A process prepares styrene polymers comprising water as sole blowing agent by mixing a polystyrene melt with water and with an emulsifying agent in an extruder, extruding the melt into a waterbath and pelletizing the cooled extrudate.

Abstract: Particulate expandable styrene polymers contain homogeneously distributed graphite particles and can be processed to give self-extinguishing foams having a density of ≦35 g/l.

Abstract: The invention relates to a process for preparing styrene polymers comprising water as sole blowing agent, by polymerizing styrene in aqueous suspension. The polymerization is carried out in the presence of from 5 to 30% by weight of recycled EPS material dissolved in styrene and comprising customary coating agents deriving from production of the EPS.

Abstract: The invention relates to a process for the preparation of expanded polystyrene particles in which polystyrene beads containing water as the sole expanding agent are expanded. The process involves the following stages: A) the polystyrene beads are pre-expanded at temperatures above 100° C., B) the pre-expanded particles are dried in dry air at temperatures between 20° and 95° C. over a period of from 1 to 10 hours, C) the dried expanded particles are further expanded with steam at temperatures ranging from 100° to 140° C., and D) the stages b and c are repeated as often as is necessary to achieve the desired bulk density.

Abstract: In a process for preparing expandable styrene polymers containing graphite particles, styrene is polymerized in aqueous suspension in the presence of graphite particles.