Flame Retardancy of Lightweight Sandwich Composites

This study proposes an innovative solution to flame-retard a sandwich composite made of unsaturated polyester resin, glass fibre skins and nonwoven core material. The strategy uses the material as flame-retardant carrier, while resin is also flame-retarded with aluminum trihydroxide (ATH). A screening fire-retardant performances materials, covered different types phosphorous additives (phosphate, phosphinate, phosphonate), was performed using cone calorimetry. best candidate selected evaluated in panel. Great were obtained ammonium polyphosphate (AP422) at 262 g/m2. material, when tested alone, did not ignite, used laminate, improved fire behaviour by decreasing peak heat release rate (pHRR) total (THR): second HRR observed for references (full monolith untreated core) suppressed this case. improvement attributed interaction occurring between two FR additives, which leads formation aluminophosphates, shown Electron Probe Micro-Analysis (EPMA), X-Ray Diffraction (XRD) solid-state 31P Nuclear Magnetic Resonance (NMR). influence add-on on core, well ATH loading matrix, studied separately optimize terms smoke release. compromise AP422 182 g/m2 160 phr ATH.