Showing papers by "American Meteorological Society published in 2011"

Improvement of Thermal Stability and Fire Behaviour of pmma by a (Metal Oxide Nanoparticles/Ammonium Polyphosphate/ Melamine Polyphosphate) Ternary System

Abstract: A design of experiment (DoE) was performed on PMMA-(ammonium polyphosphate/melamine polyphosphate/titanium dioxide) ternary system for optimizing both fire-retardancy properties and thermal stability. The software JMP® was used for this purpose. In poly (methyl methacrylate) (PMMA), progressive substitution of titanium dioxide (TiO2) nanoparticles by melamine polyphosphate (MPP) led to the reduction of the peak of Heat Release Rate (pHRR), whereas the substitution with ammonium polyphosphate (APP) first led to the reduction of pHRR followed by an increase from 9wt% APP onwards. The presence of titanium dioxide led to the increase of the time to ignition (TTI) and thermal stability. Laser Flash Analysis (LFA) measurement showed the heat insulation effect (i.e. low thermal diffusivity) of the residues that have developed during combustion. PMMA-7.5%APP/7.5%TiO2 showed the major increase of the time of combustion alongside with the decrease of pHRR due to the barrier effect. The high carbon monoxide amount released during the cone calorimeter experiment confirmed an incomplete combustion. That sample presented a ceramized structure and the formation of titanium pyrophosphate (TiP2O7) was detected by XRD measurements. TiP2O7 resulted from the reaction between APP and TiO2 upon combustion.