Study On The Properties And Flame Retardant Mechanism Of Polystyrene Foam Insulation Board Coated With Coated Flame Retardant And Impregnated Flame Retardant

At present, the application of external wall insulation technology and energy-saving materials has become the main way to achieve energy efficiency in buildings, polystyrene foam insulation board(EPS) for its light weight, good insulation properties, excellent mechanical properties, etc. occupy a very important position in the field of external wall insulation. However, in recent years, the EPS as the representative of the organic thermal insulation materials has repeatedly caused the building fire accidents, a serious threat to the lives and property of the people. So, it is very important to study the combustion property of polystyrene materials and the flame retardant modification.In this paper, the flame retardant modification of EPS was carried out by using coated flame retardant and impregnated flame retardant. And the coating structure of the EPS bead is formed. The selection of flame retardant is based on the premise of the formation of stable carbon layer. The Coated resin of Coated flame retardant is A resin, the expanded carbon layer formed by expandable graphite(EG) as the main char layer body, forming a synergistic flame retardant system with the carbon layer of APP and IFR, coating flame retardant evenly in the surface of the prefoamed polystyrene bead, and synthesis flame retardant EPS in molding method; Impregnated flame retardant using phenolic resin with good carbon performance as impregnated base fluid, then add flame retardant IFR and magnesite cement to prepare the flame retardant dipping solution. Through the phenolic resin with high carbon and other flame retardant to form stable carbon layer. The flame retardant was directly added to prefoamed polystyrene bead by vacuum impregnated method.Through the oxygen index, carbon residue rate and vertical burning test to study the effects of different types and amount of flame retardant to flame retardant properties of EPS; By tensile strength test, thermal conductivity test to study the effects of different types and amount of flame retardant to mechanical properties and thermal properties of EPS; Using scanning electron microscopy(SEM) to analysis the morphology of carbon residue samples; Using thermogravimetric analysis(TG) and differential scanning calorimetry(DSC) to study the pyrolysis process of flame retardant EPS. The conclusions are as follows:(1) Coated flame retardant with EG as the main flame retardant, Flame retardant property of EG with sulfuric acid and phosphoric acid is the best. Aiming at the problem of poor density of EG carbon layer, Joined the chemical expansion flame retardant APP, IFR. And the synergistic effect of flame retardant system was formed with EG. By co MParison: Flame retardant properties of single flame retardant system with optimal EG, IFR second, APP is the worst; The flame retardant property of EG/IFR is the most excellent in the synergistic flame retardant system; When the ratio of EG and IFR is 5:3, the amount of 8G was added: The thermal conductivity of flame retardant EPS is 0.03646W/(m·K), and the tensile strength is 0.2951 MPa, the oxygen index reached 32.1%, the burning rate is 40.85%, and the vertical burning rate is FV-0, The flame retardant layer is dense and stable, and the pyrolysis of EPS is delayed.(2) Impregnated flame retardant with phenolic resin as base fluid and the main char layer body, And add IFR, magnesite cement as a synergistic flame retardant agent. It found that the highest efficiency flame retardant is impregnated magnesite cement: When magnesite cement concentration is 15%, The thermal conductivity of flame retardant EPS is 0.03686 W/(m·K), and the tensile strength is 0.1891 MPa, the oxygen index reached 33.1%, residual char combustion rate is 37.08%, the vertical burning level is FV-0. Phenolic resin and magnesite cement collaborative form stable carbon layer, Joint play flame retardant effect.