Rheo-photoacoustic ft-ir spectroscopic method and apparatus

摘要

A rheo-photoacoustic fourier-transform infrared spectroscopic method and apparatus for examining rheological properties of materials on a molecular level. The apparatus comprises an IR spectrometer and a photoacoustic cell for generating frequency-domain photoacoustic information of a specimen under various static load conditions. Relative changes in amplitudes of certain bands in the respective spectra as a function of elongation indicate relative behavior of different molecular bonds in the material thereby to detect individually the behavior or failure mode of the respective molecular bonds. A method of detecting interfacial failure of composite polymeric material includes detecting changes in the profile of the spectrum of the surface layer at successive levels of stretching of the composite material brought about by appearance of spectral responses characteristic of the underlying layer.