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Bonding of composite materials in precise applications
Schubert, Vojtěch ; Zouhar, Jan (referee) ; Kupčák, Radim (advisor)
This work is focused on the bonding of composite materials. Related research dealing with technology of production and bonding of these materials was additionally conducted. Practical part of this thesis was set to find out what the optimal bond line thickness was for the bonding of the composites. Thus, the strength of single-lap joints (SLJ) in series of various bond line thicknesses was therein tested. A model of samples (and design of their production by wet lay-up) for the experiment is also provided in this thesis.
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Bonding of composite materials
Drkoš, Jan ; Molliková, Eva (referee) ; Němec, Karel (advisor)
The thesis deals with the analysis of the bonding of composite materials and the subsequent selection of adhesive for the specified glued joint consisting of two pieces of carbon composites. The thesis summarizes the theory of composite materials and then explains in more detail the theory of bonding together with the subsequent testing of glued joint. Another part of the thesis focuses on the market research in the field of available and suitable adhesives and the subsequent selection of the new adhesive for the glued joint, on which the epoxy adhesive was previously used. In this part, glued joints with two pre-selected adhesives were tested and then a conclusion was drawn for the selection of the most suitable adhesive.
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Precise bonding of composite materials
Tellinger, Adam ; Gregor, Lukáš (referee) ; Kupčák, Radim (advisor)
This bachelor's thesis deals with the issue of bonding composite materials. The first part of the bachelor's thesis is focused on research into the production of composite materials and gluing technologies. The content of the practical part is the design of test specimens and a preparation for their bonding with subsequent production. Furthermore, verification of compliance with the required accuracy of bonded joints when using different adhesives using 3D measurements.
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A comparison of different types of epoxy adhesives
Mihulka, Jan ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
This thesis is focused on a bonding technology. The first part describes the theory of the bonding and it is discussed the main areas of this technology. The experimental part deals with the comparison of four two-component epoxy adhesives in terms of shear strength. For the experiment it had been selected adhesives: Bison Epoxy Universal, Pattex Repair Epoxy Ultra Strong 5 min, Ergo 7430 and Letoxit LH 232. After performing the experiment, it was shown that Bison Epoxy Universal and Pattex Repair Epoxy Ultra Strong 5 min achieved the strengths stated in the datasheet. The strengths of Ergo 7430 and Letoxit LH 232 adhesives was lower than stated in their technological products, thefore, did not meet our expectations. The reason for not achieving the declared strength was probably poor dosing or insufficient mixing of ingredients.
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Mechanisms and kinetics of poly(3-hydroxybutyrate) reactions
Melčová, Veronika ; Sedláček,, Tomáš (referee) ; Bakoš, Dušan (referee) ; Přikryl, Radek (advisor)
Tato práce se zabývá reakcemi bakteriálního biopolymeru poly(3-hydroxybutyrátu) s vybranými reaktivními činidly v tavenině. Využity byly sloučeniny různých funkčních skupin; isokyanáty, karbodiimidy, alkoholy a epoxidy; a funkcionality; od dvou po polyfunkční. Cílem je charakterizovat kinetiku termické degradace tohoto polymeru během zpracování samotného a s přídavkem výše uvedených činidel v různých množstvích. Za tímto účelem bylo provedeno reologické měření sestávající ze čtyř po sobě jdoucích frekvenčních testů v rozsahu 0,1–50 Hz a ze získaných dat byl vyhodnocen parametr kvantifikující rychlost poklesu viskozity. Tento kinetický parametr umožnil porovnání účinků jednotlivých činidel. Dále byly připraveny reaktivní vzorky hnětením, při němž byl zaznamenán a diskutován kroutící moment, a také v roztocích, u kterých byla měřena viskozita. U takto připravených vzorků byly studovány tepelné vlastnosti, molekulová hmotnost a infračervená spektra. Z testovaných aditiv vykázaly nejlepší celkové výsledky v provedených experimentech polymerní karbodiimid Raschig 9000, hexamethylen diisokyanát, poly(glycidyl methakrylát) syntetizovaný pro účely této práce a poly(hexamethylen diisokyanát). Pozoruhodné je, že vzorek se 100násobným molárním přebytkem Raschigu měl o 20–30 % nižší rychlost poklesu viskozity v oblasti frekvence 0,1–5 Hz. Kromě toho byl proveden test enzymatické biologické rozložitelnosti s lipázou a v abiotických podmínkách. Nejvyšší rychlost poklesu molekulové hmotnosti vykazoval poly(3-hydroxybutyrát) aditivovaný poly(glycidylmethakrylátem).
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Precise bonding of composite materials
Tellinger, Adam ; Gregor, Lukáš (referee) ; Kupčák, Radim (advisor)
This bachelor's thesis deals with the issue of bonding composite materials. The first part of the bachelor's thesis is focused on research into the production of composite materials and gluing technologies. The content of the practical part is the design of test specimens and a preparation for their bonding with subsequent production. Furthermore, verification of compliance with the required accuracy of bonded joints when using different adhesives using 3D measurements.
|
|
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Bonding of composite materials in precise applications
Schubert, Vojtěch ; Zouhar, Jan (referee) ; Kupčák, Radim (advisor)
This work is focused on the bonding of composite materials. Related research dealing with technology of production and bonding of these materials was additionally conducted. Practical part of this thesis was set to find out what the optimal bond line thickness was for the bonding of the composites. Thus, the strength of single-lap joints (SLJ) in series of various bond line thicknesses was therein tested. A model of samples (and design of their production by wet lay-up) for the experiment is also provided in this thesis.
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Catalytic Enantioselective Desymmetrization of meso-Epoxides
Malatinec, Štefan ; Kotora, Martin (advisor) ; Baszczyňski, Ondřej (referee)
Catalytic enantioselective desymmetrization of meso-epoxides is widely used in many areas of chemistry. Such process is usually catalyzed by a transition metal complex with a chiral ligand. Recently, a synthesis of an analogue of Bolm's 2,2'-bipyridine ligand was developed and its combination with metal salts were tested in various reactions. In this master's thesis, a catalytic system composed of Sc(OTf)3/Bolm's ligand analogue was studied in alcoholysis and aminolysis of the meso- epoxides. The reaction has been extended to a broad range of alcohols providing 1,2-diol monoethers in excellent enantioselectivity up to 99% ee. The aminolysis of meso-epoxides has been optimized, as well. The catalyst loading could be lowered to 1 mol% with only marginal effects on the enantioselectivity. Key words: epoxides, enantioselective catalysis, chiral ligands.
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A comparison of different types of epoxy adhesives
Mihulka, Jan ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
This thesis is focused on a bonding technology. The first part describes the theory of the bonding and it is discussed the main areas of this technology. The experimental part deals with the comparison of four two-component epoxy adhesives in terms of shear strength. For the experiment it had been selected adhesives: Bison Epoxy Universal, Pattex Repair Epoxy Ultra Strong 5 min, Ergo 7430 and Letoxit LH 232. After performing the experiment, it was shown that Bison Epoxy Universal and Pattex Repair Epoxy Ultra Strong 5 min achieved the strengths stated in the datasheet. The strengths of Ergo 7430 and Letoxit LH 232 adhesives was lower than stated in their technological products, thefore, did not meet our expectations. The reason for not achieving the declared strength was probably poor dosing or insufficient mixing of ingredients.
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Bonding of composite materials
Drkoš, Jan ; Molliková, Eva (referee) ; Němec, Karel (advisor)
The thesis deals with the analysis of the bonding of composite materials and the subsequent selection of adhesive for the specified glued joint consisting of two pieces of carbon composites. The thesis summarizes the theory of composite materials and then explains in more detail the theory of bonding together with the subsequent testing of glued joint. Another part of the thesis focuses on the market research in the field of available and suitable adhesives and the subsequent selection of the new adhesive for the glued joint, on which the epoxy adhesive was previously used. In this part, glued joints with two pre-selected adhesives were tested and then a conclusion was drawn for the selection of the most suitable adhesive.
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