Stable water-in-oil high internal phase emulsions, containing styrene and divinylbenzene monomers and exfoliated montmorillonite, were prepared and polymerized to obtain nanocomposite microcellular materials. The porous structure was investigated by scanning electron microscopy, mercury intrusion porosimetry, and nitrogen adsorption/desorption analyses. The exfoliation of clay was investigated by X-ray diffraction and transmission electron microscopy analyses. The presence of inorganic filler did not modify the microcellular structure of the composite, while the use of modified clay significantly enhanced its mechanical properties. No influence on the thermal degradation was noted, except for materials with high clay content that tended to deteriorate at lower temperature than the other materials. (c) 2007 Wiley Periodicals, Inc.

Macromolecular monoliths were synthesised from concentrated emulsions. Matrixes with only a polyurethane network were too soft and it was necessary to add to the formulation a rigid network such as polystyrene to obtain a material with a good dimensional stability. Either unconnected or interconnected interpenetrating networks were prepared, the later by using hydroxybutyl methacrylate as a comonomer that chemically links both networks. The modifications of the mechanical properties were evaluated by estimating the Young's modulus from compression tests.