Published online by Cambridge University Press: 01 February 2011
Multifunctional nanocomposite coatings and bulk materials have been developed on the basis of a combination of purely organic, as well as hybrid organic-inorganic polymeric matrices and anisotropic synthetic and natural clays. The clays have been chemically modified in such a way that they became compatible to the polymeric matrices. Clay platelets may be separated by modification with an organic molecule that contains two or more charged functional groups. The cations or anions located between the clay sheets are exchanged with one of these organic functional groups, which results in the formation of clay platelets “coated” with charges, thereby causing a molecular dispersion. Depending on the nature of the organic molecule colored or colorless coatings and polymeric bulk materials, containing homogeneously dispersed separated clay platelets, have been obtained.
While retaining the basic functional properties of the materials new and/or improved properties have been introduced. This concerns in particular improved barrier properties, such as a decreased permeability for oxygen and water, improved corrosion resistance and increased thermal stability.
The composition of the wet coating systems is such that they can be properly applied and thermally or photo-chemically cured on various substrates such as glass, steel, aluminum and plastics. The bulk materials can be processed into final product shapes by conventional polymer processing techniques.