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. (c) 2005 Elsevier Ltd. All rights reserved.