1,721,158 research outputs found
NUOVE PROSPETTIVE PER RIVESTIMENTI RITARDATI ALLA FIAMMA/ NEW PERSPECTIVES IN FIRE RETARDANT COATINGS
No full textCatalytic Fire Retardant Nanocomposites
No full textIn this paper the chemical activity of carbon nanotubes and polyhedral oligomeric silsesquioxane during thermal degradation and combustion of polymer nanocomposites is addressed. Indeed, polymer-nanofiller systems may exhibit chemical effects capable of thermal stabilisation of polymers as well as reduction of combustion rate and heat released, owing to catalytic effects induced by the nanofillers at high temperature. Carbon nanotubes in the presence of oxygen are shown to promote oxidative dehydrogenation in polyethylene with production of a stable surface layer of carbon char that provides an effective oxygen barrier effect. A similar action is performed by metal-containing polysilsesquioxanes dispersed in polypropylene. With either carbon nanotubes or metal POSS, partial carbonisation of the polymer matrix occurs during combustion, subtracting part of the organic polymer from combustion, targeting one of the major fire retardancy ai
Ignition of polypropylene/montmorillonite nanocomposites
No full textThis paper addresses the flaming ignition of polypropylene and polypropylene-based nanoclay composites, under irradiation in a cone calorimeter. The surface temperature as a function of time was measured using thermocouples on the surface and the chemical changes occurring in the polymer leading to evolution of volatiles were studied by means of spectroscopic analyses of the surface. Thermogravimetric analyses were also carried out to study thermal and thermoxidative volatilization at variable heating rates, which correlate to the production of the critical concentration of combustible volatiles for ignition. The effect of both microdispersed and intercalated nanoclays on ignition time and ignition temperature is addressed and analysed in detail
NANOSTRUCTURE SURFACE INTERACTION WITH POLYMERS: The key factor in nanocomposite preparation
No full textFLAME IGNITION MECHANISMS IN POLYMER NANOCOMPOSITES: EXPERIMENTAL EVIDENCES AND INTERPRETATION
No full textIn this work, flaming ignition of montmorillonite clay polymer nanocomposites and microcomposites was addressed, showing variable trends in the time to ignition, as compared with the reference polymers. Temperatures on the surface layer of specimens irradiated in the cone calorimeter were measured during the test, to investigate the surface temperature at ignition. Viscosity measurement and in depth radiative absorption measurements were also carried out and correlated with ignition of polymer. Additionally, physical and chemical characterization of the condensed phase at different time, either before or after ignition, were carried out to investigate the evolution of the material during the combustion proces
Thermal shielding performances of nano-structured intumescent coatings containing organo-modified layered double hydroxides
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