Characteristic dye absorption peaks found in the FTIR spectra of coloured acrylic fibres.

The improved quality of spectra recorded using FTIR-microspectroscopy has meant that a lot more information is now obtainable from the spectra of dyed acrylic fibres. In addition to the main absorptions produced by the polymer material, additional absorptions resulting from the fibre dye are often present. An attempt has been made to explain some of the strongest and most frequently seen dye bands with the aid of spectra obtained from fibres treated with known dyes. Provided the dye concentration in the fibre is sufficient, it is possible to make some general observations on the type of dyes which have been used. Further investigation in conjunction with HPLC or FTIR-Raman spectroscopy would be useful.