THE MODIFICATION OF ALKALIN PEROXIDE MECHANICAL PULP OF TRIPLOID OF POPULUS TOMENTOSA TREATED BY LACCASE AND LACCASE/MEDIATOR SYSTEM

摘要

The Alkaline Peroxide Mechanical Pulp (APMP) of Triploid of populus Tomentosa was modified by laccase and Laccase-Mediator-System. The effects of the main parameters on the pulp physical properties were studied. They are enzyme dosages, reaction time, treatment temperature and pH value. It was found that under the optimum conditions of laccase treatment：pH 5，temperature 50°C，pulp consistency 4% and reaction time 60 min，the optimum charge of laccase was 2u/g. It was also found that the tensile strength indexes and tear indexes of the pulps treated with laccase increased significantly. The two-stage method of enzyme-mild acidic hydrolysis was adopted to isolate lignin from the APMP pulps before or after enzymatic treatments. The functional groups in all lignin samples were qualitatively and quantitatively analyzed with infrared spectroscopy and 31P-NMR techniques.