DELIGNIFICTION AND BLEACHING OF NON-TREE FIBERS WITH PEROXYMONOSULPHATE .2. FLAX AND FORAGE RAPE

The effect of peroxymonosulphate (Oxone) as an activating agent for the delignification of flax fibre and forage rape has been studied. Activation conditions were varied in the following ranges: Oxone 0-200 gL(-1) and temperature 30-70 degrees. Delignification was followed by extraction with 1 M NaOH. The residues were analysed for lignin and residual neutral sugar composition both before and after alkali extraction. Diffuse reflectance Fourier-transform infrared spectra of the residues after alkali extraction were analysed. In general, increasing oxone concentration was accompanied hg decreasing residual lignin and non-cellulosic polysaccharides for both flax and forage rape. This was also true for increasing temperature during flax fibre pre-treatments, However, increasing temperature during forage rape pre-treatments generally resulted in a decrease in residual lignin but produced a reduction in the residual anhydro-glucose. Pre-treatment of flax fibre with oxone resulted in a progressive reduction in residual colour with increasing oxone concentration and temperature. Pre-treatment of the forages rape with oxone had no effect on residual colour.