Aging of EVA/organically modified clay: Effect on dispersion, distribution and combustion behavior

Heating of polymer layered silicates nanocomposites, under air, promotes lamellas migration toward the surface. In this communication we show that aging a poly[ethylene-co-(vinylacetate)] (EVA)-organically modified clay (Cloisite 20A) nanocomposite, at temperature close to the melting point, strongly affects its combustion behavior. The thermal treatment leads to lamella exfoliation which allows an easier migration of the clay toward the surface during the early stage of combustion. This promotes the formation of a thin film, made of lamellas and polymer matrix, that traps the volatile degradation products and enormously delay the time to ignition. At the end of the combustion the film is, however, preserved.