This work presents conditions and method for obtaining foamed melamineformaldehydebutanone (Mel-F-MEK) materials of improved thermal stability. They were obtained from melamine solution in reactive solvents based on ethyl methyl ketone and 4,4-diphenylmethane diisocyanate. Some properties of obtained polyurethane foams were examined, e.g., apparent density, water absorption, dimensional stability, thermal conductivity, flammability, as well as static and dynamic thermal stability and compressive strength. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013