Preparation of γ-alumina ceramic foams employing hydrophilated polyester polyurethane sponges

A study was conducted to prepare γ-alumina ceramic foams employing hydrophilated polyester polyurethane sponges. Single phase γ-Al₂O₃ ceramic foams with high surface area and porosity were prepared by the polyurethane sponge replica method from slurries containing γ-Al₂O₃. The method for preparing these foams involved dipping the polymeric foam into a slurry containing the ceramic precursors, followed by a thermal treatment that led to the burning out of the sponge and to the pressureless sintering at elevated temperatures of the ceramic skeleton. A commercial polymeric sponge corresponding to hydrophilated polyester polyurethane with pore density of 122 ppi was tested as template for the preparation of ceramic foams. γ-Alumina was also prepared and used in the study for preparing the slurries employed in the impregnation process of polyurethane sponge.