Search for dissertations about: "cellulose aggregates"

Showing result 1 - 5 of 35 swedish dissertations containing the words cellulose aggregates.

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

   Author : Lilian Forsgren; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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). READ MORE

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

   Author : Abhijit Venkatesh; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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. READ MORE

5. 3. Structural changes during cellulose composite processing

   Author : Helena Halonen; Monica Ek; Tommy Iversen; Derek D. Gray; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; CP MAS 13C NMR; cellulose; fibril aggregation; biocomposite; compression moulding; supramolecular structure;

   Abstract : Two approaches for creating a new all-cellulose composite material have been studied: the biosynthesis of compartmentalised bacterial cellulose fibril aggregates and the compression moulding of commercial chemical wood pulps processed with only water. The objective was to study the structural changes during processing and the complexity of relating the mechanical properties of the final biocomposites to the nanoscale structure was highlighted. READ MORE

6. 4. Cellulose-water interaction: a spectroscopic study

   Author : Erik L Lindh; István Furó; Lennart Salmén; Lisbeth G Thygesen; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; cellulose; water; hydrogen exchange; deuterium; NMR spectroscopy; FT-IR spectroscopy; Kemi; Chemistry;

   Abstract : The human society of today has a significantly negative impact on the environment and needs to change its way of living towards a more sustainable path if to continue to live on a healthy planet. One path is believed to be an increased usage of naturally degradable and renewable raw materials and, therefore, attention has been focused on the highly abundant biopolymer cellulose. READ MORE

7. 5. Nanolatexes: a versatile toolbox for cellulose modification

   Author : Alexandros Efraim Alexakis; Eva Malmström; Justin Zoppe; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; nanolatexes; RAFT; PISA; adsorption; cellulose; modification; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Abstract : Cellulosic materials are widely used in our everyday lives, ranging from paperand packaging to biomedical applications. However, in most applications, cellulose must coexist with hydrophobic polymers which can be challenging due to its hydrophilic character. This has encouraged the exploration of chemical and physical modifications of cellulose. READ MORE