Use of Molecular Microspectroscopy to Characterize Pigment-Loaded Polypropylene Single Fibers

Molecular microspectroscopy was used to characterize different pigments loaded into polypropylene fibers. Single-fiber analysis by infrared, visible, and Raman microspectroscopies proved to be quite complementary for identification and quantitation of these materials. Infrared microspectroscopy was effective not only for identification of pigments loaded into the fibers, but also for quantitation of concentration levels at 1% (w/w) and greater. Visible microspectroscopy was effective for quantitation of pigment levels between the range of 0.1 and 1% (w/w). However, it may not be successful for positive identification of most pigments. Raman microspectroscopy was an effective technique for pigment identification and quantitation over all examined concentration levels provided that the sample showed no signs of fluorescence or heating effects. Quantitation for all techniques gave correlation coefficient values of 0.99+ and relative standard deviations typically ranging from 5 to 20%.