Sökning: "Modified Cellulose"

Visar resultat 1 - 5 av 161 avhandlingar innehållade orden Modified Cellulose.

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

   Författare :Merima Hasani; Chalmers tekniska högskola; []
   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

3. 2. 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

4. 3. New Methods for Enzyme Hydrolysis, Analysis, and Characterization of Modified Cellulose

   Författare :Claes Melander; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytisk kemi; Analytical chemistry; Methyl Cellulose; Reducing End; Micro Immobilised Enzyme Reactor; Mass Spectrometry; Enzyme Hydrolysis; Modified Cellulose; Substituent Distribution;

   Sammanfattning : Cellulose can be chemically modified to produce derivatives with specific properties. Knowledge of correlations between the modification reaction, substituent distribution, origin of cellulose and properties are importaint in order to design processess so as to produce derivatives with the desired properties. LÄS MER

5. 4. Investigation of Modified Cellulose and Starch via Hydrolysis and Mass Spectrometry

   Författare :Arieh Cohen; Avdelningen för arbets- och miljömedicin; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ESI-MS; Polysaccharides; Hydrolysis; Cellulases; Starch Hydrolases; Enzymatic Degradation; Enzymes; Substituent Distribution; Modified Cellulose; Mass Spectrometry; Modified Starch; Analytical chemistry; Analytisk kemi; HPAEC-PAD;

   Sammanfattning : Starches and celluloses can be chemically modified in order to affect their physiochemical properties. Modification of these carbohydrate polymers entails derivatising their free hydroxyl groups with functional groups. LÄS MER

7. 5. 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