京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21584号 / 理博第4491号 / 新制||理||1645(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 杉山 弘, 教授 秋山 芳展, 准教授 竹田 一旗 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・論文博士 / 博士(理学) / 乙第13369号 / 論理博第1573号 / 新制||理||1666(附属図書館) / (主査)教授 杉山 弘, 教授 深井 周也, 教授 秋山 芳展 / 学位規則第4条第2項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(理学) / 甲第23034号 / 理博第4711号 / 新制||理||1675(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 杉山 弘, 教授 深井 周也, 教授 秋山 芳展 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

The aim of the thesis is to determine change of mechanical properties of three types of damp polymeric materials (polyamides) depending on the water content inside material. Before testing, specimens of all three types of materials were placed inside the air conditioning chambers until equilibrium (conditioned) state was reached when the specimens received the maximum possible amount of water from the environment. A total of three conditioning levels were set, representing besides the standard level of conditioning both extreme states like state when the material was fully dried and the state where the material content the largest possible amount of water. With the increasing content of water bound in material, there is a characteristic change in the mechanical properties of the material, such as a decrease in strength and modulus of elasticity and an increase in toughness and ductility. To examine material properties change, tensile and Charpy impact tests were performed, Charpy impact tests were performed for both specimens with and without a notch. Besides changes in mechanical properties, the rate of water absorption was also observed depending on the materials and its filling.

The target of this dissertation is based on the specified shape of plastic part to develop search technology of plastic injection molds, to the technological design process and construction of injection molds, including the necessary calculations. The project includes a search and a practical sections. Based on information from a search section a suitable material was chosen, which became the basis for practical section. The practical section with basic technology calculation is complemented by filling simulation analysis and stress analysis of critical elements. A part of this dissertation is the set of the drawings.

This thesis contains of theoretical part which deals with injection molding, properties of some polymer materials are included also. Design of plastic injection mold for cover of electronic device is presented in practical part. Manufacturing parameters and injection machine selection are specified with mold structure consideration. Production costs and the final price of the plastic part are calculated in economical evaluation.

NR 20140805

Les travaux de cette thèse concernent l’étude et la modélisation rhéocinétique de systèmes chimiques réactifs à base de prépolymères PA haute température (PA-HT) pour la mise en forme de composites de hautes performances à base de matrice thermoplastique. Ils visent, plus particulièrement, le développement d’une métrologie adaptée pour le suivi de réactions très rapides sous hautes températures (supérieures à 275°C) et pouvant atteindre des degrés de conversions très élevés à des temps très courts. La viscosité du milieu atteint des valeurs supérieures à 10 Pa.s en moins d’une minute. L’intérêt d’une telle étude est double : i) l’optimisation du temps nécessaire pour injecter la matrice à l’intérieur du moule dans lequel est prédisposé un renfort fibreux. En effet, le contrôle du degré d’avancement d’un tel système thermoplastique est un paramètre critique de la mise en forme. Le but étant de garantir un degré optimum dans une pièce ; ii) une meilleure compréhension des relations structures-propriétés. Dans le cadre de ce travail, de nombreuses formulations prépolymère-allongeur de chaine ont été étudiées avec ou sans fibres de verre continues. Au vu de la forte réactivité du milieu, les moyens classiques de suivi de la réaction d’allongement ont montré leurs limites pour l’étude de ces systèmes complexes, notamment aux temps courts représentatifs de ceux pratiqués en tête d’injection et lors de l’imprégnation du renfort fibreux. A cet effet, des métrologies originales ont été développées consistant à coupler la rhéométrie, la spectroscopie infrarouge haute température et la diélectrométrie. Le but ultime étant de corréler la viscosité et l’évolution du taux de conversion dans le moule. Ensuite, une approche de modélisation rhéocinétique a été proposée pour pouvoir prédire in-situ l’évolution de la viscosité au cours du processus de la mise en forme et notamment aux temps courts. Cette chimie a ensuite été mise en situation dans un procédé de transfert instrumenté. Une fenêtre de mise en œuvre de composites PA-HT/FV a été obtenue. Enfin, les relations structure/ propriétés physiques, mécaniques et morphologiques des pièces composites obtenues ont été établies / The main objective of this work has been to develop an experimental investigation making it possible to monitor, as well as achieve a deeper understanding of the structural evolution of high temperature polyamide (PA-HT) as a thermoplastic-based composite matrix. Various formulations of prepolymer with chain extender (CA) were studied at different stoechiometry ratios and temperatures with or without continuous glass fibers. Furthermore, the interest of such a study is twofold: i) optimization of the time required for injection of the reactive system into the mold in which a fibrous reinforcement is predisposed. Thereby, the control of the conversion amount of such thermoplastic system is a critical parameter for a better control of impregnation. ii) a better understanding of structure-property relationships of the obtained thermoplastic composites. Since that the reaction kinetic was demonstrated very fast to be monitored at short times by usual technics at high temperatures above 275°C), the chemo-rheological evolutions were firstly studied ex-situ by coupling rheology with fast FTIR and dielectric spectroscopy (DRS). The ultimate purpose was to correlate the viscosity and the conversion rate in the mold. Then, a rheokinetic modeling approach was performed in order to be able to predict the evolution of the viscosity in particular at very short times (less than 2 minutes which the conversion reaches about 80%). In this work, hybrid process coupling “Reactive Extrusion”and “Resin Transfer Molding” machine (T-ERTM) equipped with an instrumented mold was designed and developed. Secondly, the hybrid process coupling “Reactive Extrusion” and “Resin Transfer Molding” machine (TP-ERTM) with an “instrumented mold” was developed with specific dielectric sensors in order to in-situ track viscosity and the extent of the reaction. The in-situ results corroborate the ex-situ ones aforementioned. Overall, a processing window was obtained for each reactive system to ensure a good preform impregnation for the manufacturing of complex and continuous glass fiber-reinforced parts. Herein, the structure/physical/mechanical/morphological properties of the obtained composites have been established.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18807号 / 理博第4065号 / 新制||理||1585(附属図書館) / 31758 / 京都大学大学院理学研究科化学専攻 / (主査)教授 杉山 弘, 教授 三木 邦夫, 教授 秋山 芳展 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18824号 / 理博第4082号 / 新制||理||1587(附属図書館) / 31775 / 京都大学大学院理学研究科化学専攻 / (主査)教授 杉山 弘, 教授 三木 邦夫, 教授 秋山 芳展 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM