LIGNIN STRUCTURAL CHANGES DURING TCF BLEACHING OF THE KRAFT PULP OF THE TRIPLOID OF POLULUS TOMENTOSA

摘要

Kraft pulp of Triploid of Polulus Tomentosa was obtained in laboratory. A TCF bleaching process -OQP was followed and the brightness of the bleached pulp reached 82%ISO. A new isolation technique was used to extract lignin samples from original wood, bleached and unbleached kraft pulps. Mn (number average molecular weights) and Mw (mass average molecular weights) distributions of all lignin samples were analyzed by Gel Permeation Chromatography (GPC). Functional groups changes of different lignin samples were quantitatively analyzed by 31P-NMR spectra to discover the disciplines of lignin structural changes during OQP bleaching process.