Sökning: "Cellulose I"

Visar resultat 1 - 5 av 257 avhandlingar innehållade orden Cellulose I.

  1. 1. Mercerization and Enzymatic Pretreatment of Cellulose in Dissolving Pulps

    Detta är en avhandling från Karlstad : Karlstads universitet

    Författare :Heléne Almlöf Ambjörnsson; Ulf Germgård; Thomas Nilsson; Storker Moe; [2013]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; alkali; carboxymethyl cellulose; cellulose I; cellulose II; cellulose dissolution; degree of substitution; enzymatic treatment; filterability; gel formation; mercerization; multivariate analytical methods; NIR FT Raman spectroscopy; sodium hydroxide; zink oxide; Chemical Engineering; Kemiteknik;

    Sammanfattning : This thesis deals with the preparation of chemically and/or enzymatically modified cellulose. This modification can be either irreversible or reversible. Irreversible modification is used to prepare cellulose derivatives as end products, whereas reversible modification is used to enhance solubility in the preparation of regenerated cellulose. LÄS MER

  2. 2. Experimental study of alkalinisation of cellulose in industrial relevant conditions

    Detta är en avhandling från Umeå : Umeå universitet

    Författare :Diana Carolina Reyes Forsberg; Ola Sundman; Bertil Eliasson; Ulf Germgård; [2018]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Mercerisation; Alkalinisation; Cellulose I; Cellulose II; Alkali cellulose; Viscose; Cellulose ether; Carboxymethylcellulose; Sodium glycolate; Sodium diglycolate; Raman spectroscopy;

    Sammanfattning : Mercerisation of cellulose pulp with a solution of NaOH is the first step of manufacturing cellulose-based value-added products, e.g. viscose fibres and cellulose ethers. During this process, cellulose transforms into a swollen crystalline structure, alkali cellulose (Na-Cell). LÄS MER

  3. 3. Chemical modification of cellulose-new possibilities of some classical routes

    Detta är en avhandling från Gothenburg : Chalmers tekniska högskola

    Författare :Merima Hasani; [2010]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Cellulose esters; Cellulose characterization; Cellulose ethers; Cationization; Cellulose nanocrystals; Crosslinking of cellulose;

    Sammanfattning : Owning to its unique structure, along with the inexhaustible renewability, cellulose has been a subject of scientific and commercial interest for over 150 years. However, given attractive structural properties, such as stiffness, hydrophilicity, stereoregularity, potential for chemical modifications and ability to form superstructures, utilization of this biopolymer is far below its potential. LÄS MER

  4. 4. Nanostructured Cellulose Biocomposites : Effects from dispersion, network and interface

    Detta är en avhandling från KTH Royal Institute of Technology

    Författare :Mohd Farhan Ansari; Lars Berglund; Jean-Francois Gerard; [2016]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wood; cellulose nanofibrils; hygromechanical properties; network structure; thermoset; polymer matrix composites; natural fiber composites; pulp fiber; strain hardening; humidity; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : The major load bearing component in native wood, cellulose nanofibrils, are potential candidates for use as reinforcement in polymer matrices. This study is based on nanocellulose composites and attempts to prepare and characterize biocomposites with high nanocellulose content and investigate the influence of nanostructure on macroscopic properties. LÄS MER

  5. 5. Design of Cellulose-based Materials by Supramolecular Assemblies

    Detta är en avhandling från KTH Royal Institute of Technology

    Författare :Tobias Benselfelt; Lars Wågberg; Torbjörn Pettersson; Joseph Schlenoff; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Adhesion; adsorption; alginate; assemblies; biodegradable; biomaterials; biopolymers; cellulose; cellulose nanofibrils; CNFs; gas barrier; hemicellulose; interfaces; ion-ion correlation; latex; layer-by-layer; metal-ligand complexes; montmorillonite; multivalent ions; packaging; PISA; polyelectrolyte multilayers; polyelectrolytes; polysaccharides; RAFT; renewable; specific ion effects; supramolecular; surfaces; sustainable; thin films; water-resilient; xyloglucan; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : Due to climate change and plastic pollution, there is an increasing demand for bio-based materials with similar properties to those of common plastics yet biodegradable. In this respect, cellulose is a strong candidate that is already being refined on a large industrial scale, but the properties differ significantly from those of common plastics in terms of shapeability and water-resilience. LÄS MER