Energy-dispersive wide angle x-ray scattering (WAXS) measurements applied to polymer characterization

A prototype x-ray equipment, initially designed and constructed in our laboratory for thickness measurement of thin silicon carbide coatings (<200 µm), is used for the characterization of epoxy polymers. The spectra delivered by wide angle x-ray scattering (WAXS) experiments allow, for instance, several kinds of characterization: (i) distinction between polymers of different chemical formulae, (ii) distinction between tightly and loosely packed networks and (iii) real-time follow-up of a curing process. Our equipment, flexible and robust, uses an energy-dispersive HpGe detector. Spectra are obtained for a constant scattering angle, i.e. without any rotation of the detector, which allows great mechanical simplicity and gain in terms of measurement time. The device can easily be set on an assembly line for the purpose of automatic non-destructive evaluation of some factory output. Alternatively, it can be set on a robot for the purpose of local inspection of a big structure.