Low Density Disc Shape Microcellular Polymeric Foams

Abstract

Porous metal oxides discs were used as moulds to produce low density microcellular disc shape foams. The oxide discs were produced by calcination of pressed hydroxide discs in vacuum at 500°C. The porous oxide discs were then impregnated with an appropriate amount of the required polymer solution. By placing the impregnated discs in a "non-solvent," the polymer inside the discs can be precipitated. Subsequent removal of the oxide produced disc shape microcellular foams. Foams made were in the density range of 100-400 mg cm^-3, and cell sizes of 1-2 μm were observed. The foams were dried by a critical point drying apparatus, using super critical carbon dioxide, and the shrinkage during drying was small (3-5%).