| 摘要 |
FIELD: chemistry.SUBSTANCE: method producing foamed polymer involves preparing a mixture, which is under pressure, of (A) a molten styrene homopolymer or copolymer, a fire-retardant amount of (B), where (B) is at least one compound 5,5-bis(bromomethyl)-2-oxo-1,3,2-dioxaphosphorinane and (C) a foaming agent, bringing the molten mixture to a temperature of at least 180°C, and then extruding the mixture in a low-pressure region such that the mixture expands and cools to form a foamed polymer containing component (B). The mixture which is under pressure further contains a melt flow accelerator. The foaming agent contains water or carbon dioxide or both water and carbon dioxide. The extruded foam plastic based on a styrene homopolymer or copolymer has density ranging from 1 to about 30 lb/ft(16-480 kg/m) and contains a fire-retardant amount of at least one compound 5,5-bis(bromomethyl)-2-oxo-1,3,2-dioxaphosphorinane.EFFECT: use of a bromated fire-retardant additive, owing to stability in extrusion conditions, which does not form considerable amount of decomposition products, providing foam plastic with excellent flame retardation and minimum drop in molecular weight of the polymer.8 cl, 1 tbl |
