Sökning: "cellulose nanocrystals"

Visar resultat 1 - 5 av 57 avhandlingar innehållade orden cellulose nanocrystals.

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. Processing and properties of thermoplastic composites containing cellulose nanocrystals or wood-based cellulose fibres

   Författare :Lilian Forsgren; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Extrusion; Cellulose nanocrystals; Cellulose; Thermal stability; Tensile properties; Wood-based fibres; Injection moulding; Composite;

   Sammanfattning : Cellulose nanocrystals (CNC) were surface modified with dialkylamines to increase the compatibility between the CNC and the polymeric matrix, and promising results were obtained, with a 300 % stiffness increase when the mixed dispersion was compression moulded on a laboratory scale. The manufacturing process was up-scaled using water-assisted mixing in a twin-screw extruder (TSE) followed by a second compounding step and injection moulding (IM). LÄS MER

4. 3. Physical properties of dispersions and composites containing surface-grafted cellulose nanocrystals

   Författare :Lilian Forsgren; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Composite; Cellulose; Thermal stability; Cellulose nanocrystals; Tensile properties; Rheology;

   Sammanfattning : The needs and requests from the society for non-fossil-based materials as well as more lightweight products are constantly increasing. The increasing awareness of the sustainability of the resources available paralleled by a growing population, point to a need for changes, if the population also aim for constantly higher standard of living. LÄS MER

5. 4. Tailoring Cellulose Nanofibrils for Advanced Materials

   Författare :Núria Butchosa Robles; Qi Zhou; Kristiina Oksman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cellulose nanofibrils; bacterial cellulose; surface modification; carboxymethyl cellulose; polyethylene glycol; chitin nanocrystals; bactericidal activity; nanofibrils orientation; water redispersability; mechanical properties; dye removal; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Cellulose nanofibrils (CNFs) are nanoscale fibers of high aspect ratio that can be isolated from a wide variety of cellulosic sources, including wood and bacterial cellulose. With high strength despite of their low density, CNFs are a promising renewable building block for the preparation of nanostructured materials and composites. LÄS MER

7. 5. Melt-processing and properties of thermoplastic composites based on ethylene-acrylic acid copolymer reinforced with wood nanocellulose

   Författare :Abhijit Venkatesh; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pulp fibers; Melt rheology; Composite; Injection moulding; Cellulose; Cellulose nanofibers; Cellulose nanocrystals; Extrusion; Mechanical properties;

   Sammanfattning : Composites reinforced with cellulose nanofibers (CNF), both modified and unmodified cellulose nanocrystals (CNC) and pulp fibers have been prepared through small-scale and large-scale methods. The composites were produced by water-assisted dispersion mixing, drying and compression moulding on the laboratory scale and by extrusion and injection moulding for the large-scale production. LÄS MER