A Method for Analysing the Gas Phase in Polyurethane Foam

A method for analyzing the gas phase in polyurethane foam is described. The gas content of the foam sample is released by grinding in a special sampling equipment made from a metal pipe. The grinding is effected by pressing the cylindrical sample towards a rotating edge at the end of the pipe. The gas released during grinding is collected in a glass syringe, permitting the total gas volume to be determined. The syringe is connected to two gas sampling valves of a gas chromatograph. In the chromatograph, the gas is analysed on two different columns. For the qualitative analysis of samples with unknown gases and for the identification of impurities, a gas chromatograph—mass spectrometer system is used. Since the sampling equipment, with the sample inserted, is flushed with an inert gas before grinding, the "true" volume of the sample can be determined and the pressure in the cells can be calculated