Sökning: "cellulose derivatives"

Visar resultat 1 - 5 av 49 avhandlingar innehållade orden cellulose derivatives.

  1. 1. Cellulose processing in ionic liquid based solvents

    Författare :Carina Olsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; esterification; cellulose; NMR spectroscopy; solution spinning; dissolution; ionic liquids; cellulose derivatives; rheology; crystallinity;

    Sammanfattning : As the most abundant polymer in nature, cellulose has an undisputed role among the raw materials to be used in a sustainable future. From its native form, in wood or straw, cellulose can be processed into products such as paper and board. LÄS MER

  3. 2. Foaming of Some Cellulose Derivatives - Initial Studies

    Författare :Kristina Karlsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rheological characterisation; Foaming; hydroxypropyl methylcellulose HPMC ; scale-up production; ethyl hydroxyethyl cellulose EHEC ; hot-mould baking; cellulose derivatives; extrusion;

    Sammanfattning : Fossil-based polymeric foams, based on polymers such as polystyrene and polyurethane, are important and widely employed materials due to their good mechanical properties relative their low density, the low price and the possibility for large-scale production. There are however a few disadvantages with these foamed products. LÄS MER

  4. 3. Mercerization and Enzymatic Pretreatment of Cellulose in Dissolving Pulps

    Författare :Heléne Almlöf Ambjörnsson; Ulf Germgård; Thomas Nilsson; Storker Moe; Karlstads universitet; []
    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

  5. 4. Mass Transport through Phase Separated Films - Effects of Ethyl Cellulose Molecular Weight on Cellulose Derivative Blends for Pharmaceutical Coatings

    Författare :Helene Andersson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Coating; Ethyl cellulose; Diffusion; Mass transport; Solvent evaporation; Molecular weight; Phase separation; Film; Hydroxypropyl cellulose; Polymer blend; Cellulose derivatives; Controlled release;

    Sammanfattning : Polymer blends are utilized for a variety of applications, not least in pharmaceutical coatings for controlled release of drugs. For instance, blends of ethyl cellulose (EC) and the water-soluble hydroxypropyl cellulose (HPC) can be used to coat drug pellets for oral extendedrelease formulations. LÄS MER

  7. 5. Foaming of cellulose derivatives and hemicellulose-containing materials

    Författare :Kristina Karlsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; β-glucan; arabinoxylan; scale-up production; hydroxypropyl methylcellulose HPMC ; ethyl hydroxyethyl cellulose EHEC ; hot-mould foaming; extensional viscosity; extrusion; hemicellulose; rheological characterisation; Foaming; xylan; cellulose derivatives;

    Sammanfattning : Fossil-based polymeric foams are important materials due to their good mechanical properties relative their low density, the low price and the possibility for large-scale production. They are widely used in cushioning, absorbing and insulation applications. There are however a few disadvantages with these foamed products. LÄS MER