Abstract: Expandable styrene polymers containinga) from 80 to 99% by weight of polystyrene,b) from 1 to 20% by weight of a styrene-soluble polymer having a softening point above 140.degree. C.,c) from 3 to 10% by weight, based on the sum of a) and b), of a C.sub.3 - to C.sub.6 -hydrocarbon as blowing agent, and, if desired, d) conventional additives,the mixture of components a) and b) having a melt flow index MFI 200/5 of from 15 to 30, have high heat distortion resistance and a high capacity for expansion.

Abstract: Expandable styrene polymers containinga) from 80 to 99% by weight of polystyrene,b) from 1 to 20% by weight of a styrene-soluble polymer having a softening point above 140.degree. C.,c) from 3 to 10% by weight, based on the sum of a) and b), of a C.sub.3 - to C.sub.6 -hyrocarbon as blowing agent, and, if desired, d) conventional additives,the mixture of components a) and b) having a melt flow index MFI 200/5 of from 15 to 30, have high heat distortion resistance and a high capacity for expansion.

Abstract: An expandable styrene polymer containinga) a styrene polymer,b) from 0.05 to 3% by weight, based on a), of water,c) from 0.001 to 1% by weight, based on a), of a finely divided organic polymer having a water absorption capacity of 10 g/g or more,d) from 0.5 to 8% by weight, based on a), of a C.sub.3 - to C.sub.6 -hydrocarbon, and, if desired,e) conventional additives in effective amounts, have good flow properties and low adhesion during prefoaming.

Abstract: Expandable molding compositions having high heat distortion resistance and containing from 80 to 99% by weight of a styrene polymer, 1 to 20% by weight of poly-1,4-phenylene sulfide, from 1 to 10% by weight of a C.sub.3 -C.sub.6 -hydrocarbon as blowing agent and, if desired, customary additives, are obtained by suspension polymerization of a solution of the polyphenylene sulfide in styrene.

Abstract: Flame-resistant, expandable styrene polymers containing a styrene (co)polymer, from 0.4 to 6% by weight of hexabromocyclododecane having a mean particle size of from 1 to 50 .mu.m, the particles being provided with a firm coating which has a thickness of from 1/100 to 1/10 of the particle diameter and is insoluble in water and styrene, from 1 to 10% by weight of a C.sub.3 - to C.sub.6 -hydrocarbon as blowing agent, and, if desired, customary additives, are distinguished by a reduced internal water content and can be processed to form foams which have an improved foam structure and high UV stability.

Abstract: Flame-resistant, expandable styrene polymers containing a styrene (co)polymer, from 0.4 to 6% by weight of hexabromocyclododecane having a mean particle size of from 1 to 50 .mu.m, the particles being provided with a firm coating which has a thickness of from 1/100 to 1/10 of the particle diameter and is insoluble in water and styrene, from 1 to 10% by weight of a C.sub.3 - to C.sub.6 -hydrocarbon as blowing agent, and, if desired, customary additives, are distinguished by a reduced internal water content and can be processed to form foams which have an improved foam structure and high UV stability.