The surface chemical composition of birch pulps prepared with the three-stage formic acid/peroxyformic acid (Milox) method was determined by means of ESCA and the results compared with a reference kraft pulp. The effect of bleaching on fibre surfaces was also studied. ESCA was also used to study Miler lignin isolated from the spent liquor from each of the three cooking stages. The amount of extractable material was considerably lower on the surfaces of unbleached Milox fibres than kraft fibres. The Miler fibres also contained somewhat less lignin than kraft pulp at the same total lignin content. Both the surface lignin and extractive contents of the Miler pulps depended on the degree of delignification. As in the case of other chemical pulps, the surface coverage of lignin and extractives on the Miler pulp fibres was higher than the average concentration in the fibres, However, at low kappa number the surface lignin and extractive contents of the Milox pulps were very low. Similar decreases in the concentration of lignin on the fibre surfaces of Miler pulps were obtained by cooking and by bleaching.
|Number of pages||6|
|Journal||PAPERI JA PUU-PAPER AND TIMBER|
|Publication status||Published - 1999|
|MoE publication type||A1 Journal article-refereed|
- Organosolv pulping
- surface chemical composition
- KRAFT PULPS