Sökning: "regenerated cellulose"

Visar resultat 1 - 5 av 45 avhandlingar innehållade orden regenerated cellulose.

  1. 1. 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

  3. 2. Chemical Modification of Electrospun Cellulose Nanofibers

    Författare :Johannes Thunberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cellulose Dissolution; Ionic liquid; Polypyrrole; Zeolitic Imidazolate Framework; Nanocellulose; Electrospinning; Cellulose; Metal-organic Framework;

    Sammanfattning : The forest industry is a large part of the Swedish economy and the export of pulp, paper and wood products constitutes 11% of the total Swedish export of goods. The main product of a pulp mill is purified cellulose, which has many great properties like biodegradability and non-toxicity. LÄS MER

  4. 3. 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

  5. 4. Investigating structural changes of cellulose using NMR spectroscopy

    Författare :Alexander Idström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; crystallinity index; NCC; ionic liquids; CP MAS 13C-NMR; hornification; native cellulose; regenerated cellulose; NMR cryoporometry; pulp; Solid-state NMR;

    Sammanfattning : In this thesis solid-state NMR and NMR cryoporometry were used to gain information of the structure of cellulose. Measurements were conducted on both native and regenerated cellulose, exposed to a range of different treatments. LÄS MER

  7. 5. Investigating cellulose structure using solid-state NMR spectroscopy

    Författare :Alexander Idström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; CNC; crystallinity index; regenerated cellulose; 2D NMR; native cellulose; pulp; Solid-state NMR; ionic liquids; CP MAS 13C-NMR; hornification;

    Sammanfattning : Cellulose is the most abundant polymer in nature and it is an important constituent in most flowers, trees, and even some animals. Cellulose has an established use in many important products, such as textile fibers, paper and paperboard, and recently new applications have received increased attention. LÄS MER