Sökning: "cellulose"

Visar resultat 21 - 25 av 847 avhandlingar innehållade ordet cellulose.

1. 21. 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

3. 22. Cellulose-based electrical insulation materials : Dielectric and mechanical properties

   Författare :Rebecca Hollertz; Lars Wågberg; Markus Biesalski; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cellulose; dielectric materials; electrical insulation; nanocellulose; nanoparticles; streamer; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : The reliability of the generation and distribution of electricity is highly dependent on electrical insulation and is essential for the prosperity of our society and a ubiquitous part of our everyday life. The present study shows how some important material properties affect the electrical properties of cellulose-based electrical insulation systems which are used together with mineral oil in high-voltage transformers. LÄS MER

4. 23. 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. 24. Macro-, Micro- and Nanospheres from Cellulose : Their Preparation, Characterization and Utilization

   Författare :Christopher Carrick; Lars Wågberg; Derek Gray; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cellulose; sphere; capsule; functionalization; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : The structure of a polymeric material has a great influence in many fundamental scientific areas as well as in more applied science, since it affects the diffusion, permeability, mechanical strength, elasticity, and colloidal properties of the materials. The results in this thesis demonstrate that it is possible to fabricate solid and hollow cellulose spheres with a cellulose shell and encapsulated gas, liquid or solid particles and with a sphere size ranging from a few hundreds of nanometres to several millimetres, all with a tailored design and purpose. LÄS MER

7. 25. Structural changes during cellulose composite processing

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

   Sammanfattning : 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. LÄS MER