Flame‐retardant mechanism of expandable polystyrene foam with a macromolecular nitrogen–phosphorus intumescent flame retardant

• DOI: 10.1002/app.44356
• Publication Date: 2016-09-16T09:09:57Z
• Authors: Gang Wang; Xue Chen; Pengju Liu; Shibing Bai
• Keywords: Intumescent; Limiting oxygen index; Polystyrene; Blowing agent; Thermogravimetry; Charring; Flame spread; Thermogravimetric analysis; Flame test

ABSTRACT Expandable polystyrene (EPS) foam is largely used as the thermally insulating external wall in buildings and constructions, but it extremely flammable because of presence almost 98% air into its porous structure, high surface‐area‐to‐mass ratio, elemental composition. Lots serious fire disasters caused by EPS have posed great threats to people's properties lives recent years. Thus, a halogen‐free, flame‐retardant urgently needed, preparation still global challenge. To solve problem that easy for form melt dripping difficult generate char layer during combustion process, macromolecular nitrogen–phosphorus intumescent flame retardant (MNP) was selected prepare good mechanical were obtained. The scanning electron microscopy characterization revealed MNP could penetrate gap between beads, thin physical coating formed on surface bead. data from thermogravimetry–Fourier transform infrared test indicated nitrogenous noncombustible gas generated pyrolysis MNP. When content increased 30%, limiting oxygen index smoking density rate EPS–MNP 28.8 23.6, respectively, UL94 V‐0 classification achieved. In addition, heat‐release rate, total heat‐release, smoke produce carbon dioxide production foams all decreased obviously; this attributed effects both condensed phases. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 44356.