| Abstract: | Modified polypropylene fibre has been prepared by incorporating a polymeric additive into the polypropylene, followed by melt spinning. Fibres with various additive concentrations were dyed with acid dyes, and the amount of dye adsorbed by the fibre was compared with the concentration of dye sites supplied to the fibre by the additive. A diffusion mechanism of dye molecules through interconnected additive particles to the fibre matrix is proposed. Colour yield was assessed by reflectance spectroscopy and photoacoustic spectroscopy. The latter was shown to be particularly suitable for measuring very dark colours. Photoacoustics can also used to detect ring dyeing of fibres at lower additive concentration. |
