Sökning: "Roland Agnemo"
Hittade 3 avhandlingar innehållade orden Roland Agnemo.
1. Ligniners reaktioner med alkalisk väteperoxid
Sammanfattning : Under alkaline conditions hydrogen peroxide can be used either as a 1ignin-degrading or a 1ignin-preserving bleaching agent. If heavy metal ions are present and/or silicate is absent in the reaction medium, hydrogen peroxide decomposes via hydroxyl radicals and superoxide ions to oxygen and water. LÄS MER
2. The Use of Lignin Derivatives to Improve Selected Paper Properties
Sammanfattning : Ved består huvudsakligen av tre typer av polymerer, cellulosa, hemicellulosa och lignin. Lignin bildas i naturen genom enzymatiskt initierad oxidativ koppling av tre olika typer av fenylpropan-enheter. Dessa bygger genom olika kol-kol- och kol-syre-bindningar upp en amorf tredimensionell polymer. LÄS MER
3. The influence of high temperature on the discoloration and degradation of carbohydrates and on hydrogen peroxide bleaching of spruce TMP
Sammanfattning : When processing wood to obtain pulp, the fibers are subjected to high temperatureat moisture levels and to the influence of metal ions. Many process developmentshave resulted in utilization of higher temperatures that induce chemical reactionsin the wood fibers. This thesis deals with some aspects of using high temperaturesin pulping processes. LÄS MER