THE EFFECT OF TRICHODERMA REESEI CELLULASE PRETREATMENT ON THE STRUCTURE AND MORPHOLOGY OF SIMAO PINE BLEACHED KRAFT PULP FIBER

The effect of Trichoderma reesei cellulase dosage on the fiber content of different lengths, the mean fiber length and mean fiber width were studied in the paper. The pulp viscosity was measured to evaluate the damage of fiber by the cellulase. Fourier transform infrared spectroscopy (FT-IR) was performed to study the cellulase treatment on the fiber chemical structure and crystallinity index. The fiber morphology difference before and after treatment was also revealed by the optical microscopy, SEM and AFM observation. The following conclusions were achieved from this work. When the cellulase dosage was lower than 3u/g, the fiber mean length slightly increased. With the further increase of cellulase dosage beyond 3u/g, the mean fiber length was less reduced than the control sample. The mean fiber width increased steadily after enzyme treatment especially after 3u/g. Enzyme treatment did change the fiber chemical structure and crystallinity index through FT-IR analysis. The optical microscope and SEM analysis showed the surface of cellulase treated fiber had some fluffing phenomenon and there was obvious intertexture between fiber and fiber. AFM images further demonstrated that the fiber surface of controlled pulp was covered by primary layer. After enzyme treatment, the primary layer of fiber cell wall was peeled off.