Sökning: "cellulose degradation"

Visar resultat 1 - 5 av 130 avhandlingar innehållade orden cellulose degradation.

  1. 1. Free radical mediated cellulose degradation

    Författare :Erik Johansson; KTH; []
    Nyckelord :free radicals; cellulose; polymer; average chain length; bleaching; TCF; ozone; degradation;

    Sammanfattning : This thesis addresses the mechanisms involved in cellulosedegradation in general and Totally Chlorine Free (TCF) bleachingof pulp in particular. The thesis shows that the cellulosedegradation during high consistency ozone bleaching is explainedby free radical chain reactions. LÄS MER

  3. 2. Cellulose degradation in pulp fibers studied as changes in molar mass distributions

    Författare :Rickard Berggren; KTH; []
    Nyckelord :cellulose; kraft pulp; birch; spruce; ozonation; acid hydrolysis; degradation; MMD; size-exclusion chromatography; light scattering; molar mass; chain scission;

    Sammanfattning : In this thesis, size-exclusion chromatography (SEC) of woodpolymers dissolved in lithium chloride/N,N-dimethylacetamide(LiCl/DMAc) has been used to characterize the molar massdistributions (MMD) of wood polymers in pulp fibers afterchemical degradation.Characterization of birch kraft pulps subjected to ozonedegradation and acid hydrolysis, respectively, rendereddifferent changes in the MMD. LÄS MER

  4. 3. Carbohydrate degradation and dissolution during Kraft cooking : Modelling of kinetic results

    Författare :Dan Johansson; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kraft cooking; softwood; hardwood; cellulose; xylan; glucomannan; degradation; dissolution; Chemical engineering; Kemiteknik; Chemical Engineering; Kemiteknik;

    Sammanfattning : Chemical pulp fibres from wood are commonly used in products associated with packaging as well as with printing and writing. The prevalent way of liberating fibres is by subjecting wood chips to Kraft cooking. This process has a history of almost 130 years and should be both well described and well established. LÄS MER

  5. 4. Cellulose degradation in water

    Författare :Nils Edberg; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  7. 5. Hydrolytic and Oxidative Mechanisms Involved in Cellulose Degradation

    Författare :Anu Nutt; Jerry Ståhlberg; Henrik Stålbrand; Uppsala universitet; []
    Nyckelord :Biochemistry; cellobiohydrolase; cellulase; cellulose; cellobiose dehydrogenase; endoglucanase; kinetics; synergism; competitive binding; Biokemi;

    Sammanfattning : The enzymatic degradation of cellulose is an important process in nature. This thesis has focused on the degradation of cellulose by enzymes from two cellulose-degrading fungi, Hypocrea jecorina and Phanerochaete chrysosporium, including both the action of the individual enzymes and their synergistic interplay. LÄS MER