A polymeric nanocomposite is a material characterized by the homogeneous dispersion "Dispersion (physical)") of filler particles "Particle (chemistry)") of nanometric dimensions inside a polymer matrix. Silicate and metallic nanoparticles are generally used as fillers.

In conventional type composite polymers (that is, to which a non-nanostructured inorganic component has been added, for example glass fiber reinforced plastics) there is a net separation at a macroscopic level between the organic and inorganic phases, which represents a limitation to the improvement of polymeric materials; The advantage of polymer/phyllosilicate nanocomposites is that they allow this limit to be overcome, improving the mechanical and thermal characteristics and permeability of the polymer itself, with the addition of minimal quantities (of the order of 5%) of silicates. It is important to emphasize that such improvements do not come at the expense of color, processability or apparent density.

These types of materials are having wide application, especially in the field of food packaging, due to their barrier property to gas penetration, up to five to fifteen times greater than that of pure polymer and filled polymers that often contain up to 20 - 30% of siliceous material (mica, talc or calcium carbonate). On the other hand, silicate/polymer nanocomposites also have improved flame retardancy; The tests show that the peak speed of heat emission, which is a measure of the flammability of the material, in the case of a nanocomposite becomes 60 to 80% lower than that of a pure polymer. At the same time, mechanical properties exhibit significant improvements, such as increased toughness and abrasion resistance.