Lyotropic liquid crystalline polymer solutions containing rod-like polymer can be oriented changing the concentration and/or applying a shear field. These solutions can be processed into fibers and films with well-developed, nearly uniaxial orientation providing high stiffness and rigidity. The solutions studied in this dissertation were comprised of rod-like poly-$p$-phenylene benzobisthiazole (PBZT) and coil-like Zytel${\sp{\circler}}$330 (Z33) in methane sulfonic acid and a methane sulfonic acid/poly-phosphoric acid blend. The isotropic-nematic phase boundary for the binary, ternary and quaternary systems was determined from the concentrations corresponding to the maxima in zero-shear viscosity. These "critical concentrations" were found to be in close proximity to the concentrations corresponding to the appearance of a nematic phase as determined by optical microscopy. For the binary and ternary solutions (in addition to many case studies), the theory of Flory for the prediction of the isotropic-nematic phase boundary based on thermodynamics provided an adequate fit of the concentrations corresponding to the viscosity maxima in addition to the critical concentrations observed by microscopy. For quaternary solutions, the aspect ratio of the PBZT component corresponding to the theoretical fit was significantly lower than that expected based on molecular structure. The unique structure of the PPA solvent component is believed to be attributed to this observation (non-negligible energies of interaction). For all of the solutions, a partitioning of the phases was found to occur in which the addition of the coil-like Z33 decreased the amount of rod-like PBZT necessary for the appearance of a biphasic region. The zero-shear viscosity for the isotropic solutions was determined almost entirely by the concentration of the PBZT component and not significantly influenced by the concentration of the Z33 component. However, the critical concentration was significantly reduced by the addition of the Z33. The Doi theory did not provide an adequate fit of the concentration dependence of the zero-shear viscosity for binary and ternary solutions while it was quite successful for the quaternary solutions. The viscosity for solutions of higher total polymer concentration were found to be predominantly dependent on deformational history. This suggests that molecular ordering attained by the concentrated solutions through shearing does not relax significantly to result in a system that is independent of deformational history. The zero-shear viscosity for a concentrated solution is therefore an "apparent" one since it cannot be entirely retained after being subjected to higher shear rates.

This dissertation discusses studies on the physical properties of poly(ether ether ketone) (PEEK). Several investigations involving the crystallization and melting behavior of PEEK, crystallization of PEEK on carbon fibers, and uniaxial draw of PEEK are presented. The double-melting behavior of isothermally crystallized PEEK was investigated using differential scanning calorimetry (DSC) and wide and small-angle X-ray scattering. The double-melting was found to be due to a crystal reorganization on heating. The low and high-melting endotherms are the sum of four contributions: Melting of the original crystals, their recrystallization, remelting of recrystallized crystals and melting of core crystals. Material parameters such as the thermodynamic melting point (384, 389$\sp\circ$C) and surface free energy (39 erg/cm$\sp2$) of the PEEK crystal were measured. The isothermal and non-isothermal crystallization of PEEK was found to depend on the previous thermal history. This was explained by a persistence of small residual crystalline regions up to the thermodynamic melting point, at which the infinitely large and perfect crystals melt. The crystallization of PEEK on carbon fibers was studied by DSC, electron and optical microscopy. The control, characterization, and effect of the crystalline interface between PEEK and carbon fiber were investigated. The carbon fiber surface was found to compete with nuclei in the PEEK matrix for crystallization growth. Reducing the number of nuclei in the matrix by long preheating favored PEEK crystallization on the carbon fiber, resulting in about 2 times stronger interfacial bond as indicated by transverse tensile tests. PEEK films and rods were solid-state extruded at 154 and 310$\sp\circ$C. The tensile mechanical properties were improved by drawing. The modulus and strength were increased up to 6.5 GPa and 600 MPa, respectively. The structural evolution of PEEK on drawing was studied using wide-angle X-ray diffraction and birefringence. The c axis crystal orientation function (up to 0.67) and birefringence (up to 0.30) were increased with draw ratio.

Depuis une quarantaine d’années, les déchets ménagers et leur gestion sont assimilés à un enjeu écologique global. Alors que se popularisent les discours défendant une conception durable du développement, nos poubelles se multiplient. Qu’aspirons-nous à préserver lorsque, l’enjeu planétaire invoqué, un gouffre intermédiaire se dessine et nous invite à interroger ce lien communément admis entre déchets et pratiques de protection de l’environnement. Notre thèse consiste à affirmer que, sous couvert de leur « environnementalisation », et malgré l’inflation du temps et de l’espace qui leur sont consacrés, les déchets restent marqués par l’oubli des enjeux sociaux, techniques, matériels qui les caractérisent. Cet aveuglement, individuel et collectif, neutralise toute possibilité de penser le déchet comme indice : il voile sa fonction mémorielle et le condamne à n’être appréhendé que comme ce qui doit disparaître, que comme quantité de matière à contrôler, à éliminer. Le déchet durable est l’oxymore qui vise à problématiser cette multiplicité des modes de présence du déchet aujourd’hui. S’inspirant des figures du chiffonnier ou de l’archéologue, notre enquête socio-anthropologique s’applique à suivre ces déchets ménagers, depuis d’incertains océans de plastique jusqu’à quelques lombricomposteurs parisiens. A partir de cette confrontation à la matérialité, aux territoires et aux pratiques du déchu, il s’agit d’affirmer que là où la présence irrévocable des déchets est décrite comme un problème, la question de notre présence aux déchets se pose inévitablement. / Over the past forty years, household waste and its management have been assimilated to a global environmental issue. While sustainable development is becoming a pressing issue, the number of our garbage bins is increasing. So what is it that we aim to preserve when we are dutifully sorting out our garbage? Between the very local gesture of discarding and the global environmental issue, there is a tremendous gap. The link between everyday practices of waste and environmental issues is so underdetermined that it has to be analysed. The main claim of this dissertation is that despite a growing concern with environment and the increasing time and space devoted to waste management, we remain unaware of the social, technological and material issues at stake. Because of this individual and collective blindness waste is not seen as a clue: as its memorial function is neglected waste is still perceived as what has to disappear, as a material quantity that has to be controlled and eliminated. The en-durable waste is an oxymoron that leads to further investigate the multiple modes of presence of waste in today’s life. Inspired by the personae of the ragman and of the archaeologist, this socio-anthropological investigation follows household waste from uncertain oceans of plastic to few Parisian vermicompost bins. Based on this confrontation to the materiality of waste, to the territories and to practices of wasting, this dissertation claims that where the unavoidable presence of waste is described as a problem, it is question of our presence to waste that is at stake.

This Diploma thesis is aimed at various ways of connecting electrical parts in car locks. This part of the thesis includes technologies of electric cables, printed circuit boards, lead frames, 3D-MID technology and technology of electroconductive plastics materials. Listed technologies are compared. The aim of the practical thesis portion is the application of electroconductive plastic materials on the given part. For this purpose necessary changes were designed in the provided small series injection mold. The thesis also includes drawing documentation of the designed construction changes in the injection mold, as well as economic appraisal of the prototype manufacturing fees.