Considerations for Raman spectroscopic determination of polyene length distribution in degraded poly(vinyl chloride)

Abstract

Practical complications in the quantitative Raman spectroscopic determination of the polyene sequence length distribution in degraded PVC samples were found. If samples are measured directly, i.e. without dissolving them, the distribution of polyenes changes during the Raman experiment if power densities above 20 W/mm 2 are used. Lower power densities or short exposure times (<1 min) must be used to avoid these effects. The direct method turned out to be an appropriate method for the quantitative determination of the polyene length distribution in lightly degraded PVC (<0.05 % HCl loss)