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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Polyfluorinated compounds via free-radical reactions of alcohols and diols

Farren, Christopher January 1998 (has links)
Site-selective incorporation of fluorocarbon substituents into organic molecules is a field of continuing interest, and a variety of approaches have been reported. The research described within this thesis is concerned with the functionalisation of C-H bonds adjacent to primary or secondary hydroxyl units via free-radical additions to fluoroalkenes. A range of cyclic and acyclic alcohols and diols have been functionalised in this manner, and both substituent and electronic effects on the radical process have been investigated. Further functionalisation of the polyfluoroalkylated products has been performed, giving a range of new fluorinated systems, and an investigation into the chemistry of these systems has begun.
2

Polyfluorinated systems resulting from free radical addition reactions

Olivarès, Christel M. January 2001 (has links)
The first part of this work was to synthesise partially fluorinated reactive compounds and then to study their reactivity towards nucleophiles and electrophiles. These reactive compounds were obtained in a two step process from both cyclopentane and adamantane and in a three step process for cyclopentanol. The first step was the free radical addition of the cycloalkanes, cycloalcohol to hexafluoropropene via thermal and/or radiochemical alkylations. For the cyclic alkane derivatives, the second step was a stereospecific dehydrofluorination of the fluorocarbon chain, whereas for the cyclic alcohol, a dehydration and then dehydrofluorination were performed to give the conjugated diene. Finally, the fluoroalkene reactivity was studied via nucleophilic and electrophilic addition reactions. The second part of my work was to study the free radical addition of tertiary amines to hexafluoropropene, an example is illustrated below.
3

Compréhension du phénomène d’adhésion d’un gel polymère réalisé par extrusion sur substrat aluminium : application au contact électrode-collecteur d’une supercapacité / Study of the adhesion of a polymer gel produced by extrusion on an aluminium substrate : application for the collector-electrode contact of a supercapacitor

Akkoyun, Meral 13 November 2012 (has links)
L’objectif de ce travail est d'envisager les modifications de formulation ou de procédé dans la technologie de geltrusion développée par Batscap pour augmenter la fiabilité des supercondensateurs en limitant l'autodécharge. La technologie repose sur l’extrusion simultanée de polymères (PVDF, PVDF-HFP), d’un solvant (PC) et de charges (CA, NC). Le mélange réalisé en extrusion bivis est ensuite filmé et laminé sur le collecteur en aluminium. Dès lors, il a été fondamental de chercher à comprendre les interactions entre les différents composants de l’électrode, avec l’étude de la miscibilité du système ternaire polymère/polymère/solvant puis l’étude de l’adsorption du solvant sur les charges. Cette démarche a permis une meilleure compréhension des phénomènes impliqués en passant par une caractérisation approfondie du complexe, dans sa formulation actuelle aux différentes étapes du procédé. Ensuite, des modifications de formulations ont été envisagées. En particulier, l'effet de la structure et de la masse molaire des polymères sur l’adhésion a été étudié. Dans tous les cas, il a été envisagé de tester les possibilités offertes par l'utilisation d'un solvant différent (DMSO). Ce dernier étant un meilleur solvant du PVDF est plus facile à éliminer que le PC. Enfin, à partir des données rhéologiques du mélange, une modélisation mécanique, en utilisant le modèle de Maxwell à plusieurs temps de relaxation, a été menée dans l'opération de laminage du mélange en prenant en compte un comportement viscoélastique du gel. Toutes ces études ont permis de conclure sur les modifications pertinentes de la formulation ainsi que des conditions du procédé / The objective of this work is to consider changes in formulation or process of the geltrusion technology developed by Batscap to increase the reliability of supercapacitors by limiting self-discharge. The technology is based on the simultaneous extrusion of polymers (PVDF, PVDF-HFP), solvent (propylene carbonate) and fillers (activated carbon, carbon black). The mixture carried out in a twin-screw extrusion is then filmed and laminated on the aluminium collector. Therefore, it was important to understand the interactions between the different components of the electrode, and especially to study the miscibility of the ternary system polymer/polymer/solvent and also the adsorption of solvent on fillers. This approach has allowed a better understanding of the phenomena involved through a characterization of the complex, in its current form at different stages of the process. Then, changes in formulations were considered. In particular, the effect of the structure and molecular weight of the polymers on adhesion was studied. In all cases, it was envisaged to test the possibilities offered by the use of a different solvent (dimethyl sulfoxide). The latter being a better solvent for the PVDF, is also easier to remove than propylene carbonate. Finally, from the rheological data of the mixture, a mechanical modeling, using the multimodal Maxwell model, was conducted in the lamination step taking into account of the viscoelastic behavior of the gel. All these studies allow us to conclude on the relevant changes in the formulation and process conditions
4

Experimentelle und theoretische Untersuchungen der Dissoziationen von Tetrafluorethen, Hexafluorpropen und Hexafluorcyclopropan / Experimental and theoretical analysis of the dissociation of tetrafluoroethene, hexafluoropropene and hexafluorocyclopropane

Sölter, Lars 27 June 2014 (has links)
No description available.

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