Abstract
Nanocomposites are a new class of polymer systems. Modified layered silicates as fillers are dispersed at a nm-level within a polymer matrix. For nanocomposites new and extraordinary properties are observed. The thermal stability and the flame retardancy of polymers forming nanocomposites are improved. The flame retardancy mechanism of layered silicate nanocomposites is based on the char formation and its structure; the char insulates the polymer from heat and acts as a barrier, reducing the escape of volatile gases from the polymer combustion. The cone calorimeter is a very useful tool to investigate the properties of flame retardancy. The combination of organoclays with traditional flame retardants is a general way to improve the flame retardant properties of polymers.