Sökning: "xylan"

Visar resultat 11 - 15 av 90 avhandlingar innehållade ordet xylan.

  1. 11. Improved Usage of Wood Raw Material through Modification of the Kraft Process

    Författare :Daniel Tavast; Elisabet Brännvall; Mikael Lindström; Martin Lawoko; Kerstin Forsberg; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; kraft process; impregnation; xylan; spruce; Chemical Engineering; Kemiteknik;

    Sammanfattning :    The kraft process is a complex system with many variables, and though the process is fairly well understood, there is still much we do not know.    This thesis examines some aspects of the kraft process that could prove to be of interest for the pulp and paper industry, specifically, the impact of wood chip impregnation and of the chemical structure of xylan on spruce kraft pulp. LÄS MER

  3. 12. Mechanisms of Biopolymer Solvation: Development of a two-component ionic liquid solvent system

    Författare :Susanne Bylin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; ionic liquids; solvation; mechanism; xylan; lignin; cellulose; wood components;

    Sammanfattning : Ionic liquids are of potential interest in the processing of lignocellulosic biomass, and/or its components, for the purpose of producing renewable and value-added biomaterials. An understanding of how solvation can be achieved and the way in which the feedstock biopolymers are affected, however, needs to be gained prior to a viable implementation. LÄS MER

  4. 13. Extraction of polymeric rapeseed straw hemicelluloses for renewable films

    Författare :Antonia Svärd; Ulrica Edlund; Elisabet Sjöholm; Emma Strömberg; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; rapeseed straw canola straw; hemicellulose; xylan; mannan; extraction; characterization; severity factor; hemicellulose film; Kemi; Chemistry;

    Sammanfattning : Polymeric hemicelluloses with high molecular weight were extracted from rapeseed straw with a straight forward hydrothermal extraction method, evaluated and refined by statistical factorial screening design and ‘severity factor’ analysis. The influence of the extraction conditions, time, temperature and pH of the extraction liquid, on the composition, molecular weight, yield and properties was unveiled. LÄS MER

  5. 14. On the Mechanism of Assembly of Xylans onto Cellulose Surfaces

    Författare :Åsa Linder; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aggregation; Xylan; cellulose; surface structures; assembly;

    Sammanfattning : Cellulose is the most abundant biopolymer on earth and the major component in cell walls of wood and terrestrial plants. Commercial applications include paper, plastics, hygiene and pharmaceutical products. The composition and morphology of cellulose surfaces affect the product properties. LÄS MER

  7. 15. Wood Hemicelluloses - Fundamental Insights on Biological and Technical Properties

    Författare :Jennie Berglund; Mikael Lindström; Gunnar Henriksson; Francisco Vilaplana; Jakob Wohlert; Martin Lawoko; Maija Tenkanen; KTH; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; hemicellulose; wood; glucomannan; xylan; structure; acetylation; flexibility; solubility; interaction with cellulose; stability.; hemicellulosa; trä; glukomannan; xylan; struktur; acetylering; flexibilitet; löslighet; interaktion med cellulosa; stabilitet.; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : Hemicelluloses are a group of heterogeneous polysaccharides representing around 30 % of wood where the dominating types are xylans, glucomannans and xyloglucans. Hemicelluloses complex molecular structure makes it difficult to understand the relationship between structure and properties entirely, and their biological role is not yet fully verified. LÄS MER