Flame-retardant polymer foams with halogen-free flame-retardant agents containing phosphorous on a sugar basis

Flame retardant system comprises (a) at least one flame protection component comprising phosphorylated di-, oligo- or poly-saccharide compound with 0.5-40 wt.% of phosphorus content, and (b) at least one flame protection component comprising elemental sulfur or organic sulfur compound with a sulfur content of 5-80 wt.%, and an organic peroxide. Independent claims are included for: (1) a method for flame retardant finishing of foamed or unfoamed polymers, comprising mixing a melt of the polymers or the monomers from which the polymer is produced, with the flame protection system; (2) a polymer composition comprising one or more polymers and the flame protection system; (3) preparing an expandable styrene polymer comprising mixing a blowing agent and the flame protection system and optionally further auxiliary additives by static and/or dynamic blender at a temperature of 150[deg] C into a styrene polymer melt, cooling the styrene polymer melt to a temperature of 120[deg] C, discharging the styrene polymer melt by a nozzle plate with holes, whose diameter of a nozzle exit is 1.5 mm, and granulating the melt directly behind the nozzle plate under water with a pressure of 1-20 bar; and (4) preparing a styrene extrusion foam material comprising (a) heating a polymeric component containing the styrene polymer to form the polymer melt, (b) introducing a blowing agent component into the polymer melt for the formation of a foamable melt, (c) extruding the foamable melt in a low pressure range under foaming to an extrusion froth, and (d) adding the flame protection system and the optionally further auxiliary additives into the steps of (a) and (b).