PHYSICAL CHARACTERIZATION OF ENZYMATICALLY MODIFIED KRAFT PULP FIBERS

Douglas-fir kraft pulps were treated with an enzyme preparation contai ning both cellulase and xylanase activities. Treatments resulted in th e solubilization of 21.1% the xylan and 1.8% of the cellulose. Changes in fiber and paper properties were observed. Monitoring pore volume, degree of polymerization, crystallinity, FT-IR spectra, and scanning e lectron microscopy helped elucidate changes in fiber composition and m orphology. Data indicate a decline in intrinsic fiber strength due to an erosion of the fiber surface. Reduction in paper strength resulted from the collective effects of decreased intrinsic fiber strength and the reduction in the degree of polymerization of a large portion of th e hemicellulose component of the fibers, as well as fiber defibrillati on and fines hydrolysis. (C) 1997 Elsevier Science B.V.