Sökning: "Ulf W. Gedde"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden Ulf W. Gedde.

1. 1. Degradation of acrylonitrile butadiene rubber and fluoroelastomers in rapeseed biodiesel and hydrogenated vegetable oil

   Författare :Shahin Akhlaghi; Ulf W. Gedde; Jean-Luc Gardette; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Degradation; Acrylonitrile butadiene rubber; Fluoroelastomers; Biodiesel; Hydrotreated vegetable oil; Cavitation; Bound rubber; Dehydrofluorination.; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Biodiesel and hydrotreated vegetable oil (HVO) are currently viewed by the transportation sector as the most viable alternative fuels to replace petroleum-based fuels. The use of biodiesel has, however, been limited by the deteriorative effect of biodiesel on rubber parts in automobile fuel systems. LÄS MER

3. 2. Long-term performance of poly(vinyl chloride) cables : mechanical and electrical performances and the effect of plasticizer migration

   Författare :Maria Ekelund; Ulf W. Gedde; Minna Hakkarainen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Poly vinyl chloride cables; ageing; mechanical properties; plasticizer migration; Polymer chemistry; Polymerkemi;

   Sammanfattning : Cables insulated with plasticized poly(vinyl chloride) were aged at temperatures between 80 and 180 °C in air and their conditions were assessed by indenter modulus measurements, tensile testing, infrared (IR) spectroscopy, differential scanning calorimetry (DSC) and liquid chromatography (HPLC). Electrical testing of oven-aged cable samples was performed in order to relate the electrical functionality during a high-energy line break accident to the mechanical properties and to establish a lifetime criterion. LÄS MER

4. 3. The cell wall ultrastructure of wood fibres : effects of the chemical pulp fibre line

   Författare :Jesper Fahlén; Ulf W. Gedde; Drek G. Gray; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical engineering; atomic force microscopy; cellulose; cell wall; drying; fiber; Kemiteknik; Chemical engineering; Kemiteknik;

   Sammanfattning : Knowledge of the ultrastructural arrangement within wood fibres is important for understanding the mechanical properties of the fibres themselves, as well as for understanding and controlling the ultrastructural changes that occur during pulp processing. The object of this work was to explore the use of atomic force microscopy (AFM) in studies of the cell wall ultrastructure and to see how this structure is affected in the kraft pulp fibre line. LÄS MER

5. 4. Combustion dynamics and melt dripping of ethylene-acrylate copolyer composites

   Författare :Roland H. Krämer; Ulf W. Gedde; Mats Jonsson; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; methacrylic acid; ethylene; calcium carbonate; ionomer; nanoparticles; intumescence; halogen-free; flame retardant; melt dripping; Polymer chemistry; Polymerkemi;

   Sammanfattning : The degradation and combustion of blends of ethylene-acryalte copolymer with calcium carbonate and silicone were studied by a combination of flammability tests, in-situ measurements and analytical experiments. Compounds of poly(ethylene-co-methacrylic acid) blended with precipitated calcium carbonate nanoparticles were prepared. LÄS MER

7. 5. Melt flow and surface stability effects on polymer flammability : A study on polystyrene, flexible polyurethane foam and polyolefin composites

   Författare :Roland H. Krämer; Ulf W. Gedde; Norman C. Billingham; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Melt; flow; dripping; collapse; combustion; pool fire; feed‐back; gasification; heat release; flammability; nanocomposites; molar mass; intumescence; polyurethane; Polymer chemistry; Polymerkemi;

   Sammanfattning : Our ability to accurately determine the flammability properties of polymers is hampered bythe erratic effects of deformation and liquid flow that occur during polymer combustion.This study aims to improve the understanding of such effects at several levels: The often obvious impact of melt flow on standardized flammability test methods forelectrical appliances is described to identify the need and to motivate others to worktowards an improved material characterization. LÄS MER