The C la, N is, and 0 ls excitation spectra of model methylenediphenyldiisocyanate (MDI) polyurethane’s with well known structures have been recorded using electron energy loss spectroscopy (EELS) in an electron microscope. These spectra are compared to the core excitation spectra of selected small molecule analogue species (recorded by gas phase EELS) in order to identify transitions characteristic of various structural components found in polyurethanes. A more detailed report on the small molecule analogue spectra is presented in the following article. Spectral features characteristic of the different structural components in polyurethanes are identified in the spectra of the model polymers. These can be used as the basis for chemical studies of micron or submicron sized segregated phases in flexible polyurethane polymers.

Keywords: polyurethanes · phase segregation · analysis by core excitation spectroscopy

ã 1995 John Wiley & Sons, Inc