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Polymerization of Lactides in the Melt
Horkel, Ondřej ; Tomala, Libor (referee) ; Petrůj, Jaroslav (advisor)
This bachelor thesis deals with the problematics of Lactide polymerization in the melt. Theoretical part summarizes properties of lactic acid, lactides and polylactides as well as currently used methods of their preparation. In experimental part, a set of three experiments was designed, namely dependance of viscosity average molecular weight on catalyst concentration, polymerisation temperature and polymerisation time. This was achieved by measuring cinematic viscosity using Ubbelohde viscosimeter. As a result of these experiments, it was found that one of posssible combinations of conditions resulting in high molecular weight polymers is the following: concentration ratio of catalyst towards lactide 110–4, polymerisation teperature 160 °C and polymerisation time 3 hours.
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Lanthanocene Catalysts for Synthesis of Polymers Applicable in Medicine
Slanina, Ondřej ; Kábelová, Božena (referee) ; Richtera, Lukáš (advisor)
The theoretic part of the thesis focuses on materials used in medicine. The metallic, ceramic, glass-ceramic and polymer materials are systematically described. The biocompatibility of the materials and possible threads of their usage for manufacturing of medicinal devices and implants are emphasized in the discussion. The work is focused especially on polymer materials. Different types of polymerizations are summarized with the accent on the preparation of biodegradable materials. In the practical part the synthesis of two organometallic bis(pentamethylcyclopentadienyl) sandwich complexes with holmium and gadolinium as a central atom designed for preparation of materials suitable for biomedicine is proposed.
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Gel polymer electrolytes with nanoparticles
Szotkowski, Radek ; Sedlaříková, Marie (referee) ; Jahn, Michal (advisor)
This master‘s thesis concerns gel polymer electrolytes formed on a methyl methacrylate base with selected types of nanoparticles. In the thesis are also analyzed the methods for measuring electrochemical properties. The practical portion deals with sample preparations of gel polymer electrolytes with different contents of alkaline salt in a solvent, creating gels with different nanoparticle content and comparing gel polymer electrolytes polymerized with heat and UV radiation. The thesis deals with the evaluation of these samples from the viewpoint of electrical conductivity and potential windows as well as thermal analysis of selected samples.
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Synthesis of Lanthanidocene Based Compounds
Pospíšek, Marek ; Zmrzlý, Martin (referee) ; Richtera, Lukáš (advisor)
The aim of this bachelor thesis is to summarize the issues of the polymerization catalytic systems based on lanthanidocene complexes. These complexes are subsequently divided by the structure into four basic groups. One part of this work deals with an overview of the most interesting results of the catalytic systems, which are then analyzed and assessed either in its entirety or point of view of catalytic activity, living mechanism of polymerisation and stereo or regioselectivity. The focus is also placed on type of monomers or the conditions of polymerization. In this part of thesis are also described general methods for their synthesis. Found analogies and generalization are commented from the point of view of the design of the catalytic systems for the purpose of choosing the stereo or regioselectivity, molar mass and its distribution. This gives significance to these complexes as catalytic systems for obtaining the required polymer properties. The acquired knowledge is used for the theoretical design of the catalytic system for controlled polymerization.
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PLA Synthesis in Solution
Svítil, Jan ; Zdeněk, Přikryl (referee) ; Petrůj, Jaroslav (advisor)
This thesis is studying PLA syntheses using polymerization of lactides in solution. Theoretical part deals with properties and production of lactic acid, lactides and polylactides. In the experimental part, possibilities of lactides polymerization in solution has been summerised and verified. Syntheses were performed via “solvothermal” method using 7 solvents (toluene, chloroforme, 1,2-chlorobenzene, acetone, tetrahydrofurane, cyclohexane and hexane). Using hexane as solvent, at concentration ratio catalyzer/lactide 1 : 1 000, polymerization temperature 160 °C and reaction time 20 h, polylactide of viscosity average molecular weight 179 000 gmol–1 was synthetized from the lactide.
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Gel polymer electrolytes modified by ionic liquids with aprotic solvents
Pospíšilová, Michaela ; Sedlaříková, Marie (referee) ; Jahn, Michal (advisor)
This graduate thesis is focused on measuring the electrical conductivity of the gel polymeric electrolytes, their preparation and deals with the changes of the performance ratio of the individual substances in gel electrolyte The theoretical part deals with electrochemistry, gel electrolytes, the conductivity of electrolytes, gel electrolytes preparation, methods used to evaluate the measured results and on the properties of the ionic liquids. In the practical part is summarized the process of preparing gel electrolytes, the chemicals to prepare the gels with ionic liquids. The results are evaluated by using impedance technique and linear voltammetry, there are calculated the values of the electrical conductivity of the electrolyte and potential windows.
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Gel Polymer Electrolytes for Electrochemical Power Sources
Jahn, Michal ; Bartušek, Karel (referee) ; Paidar,, Martin (referee) ; Sedlaříková, Marie (advisor)
Dissertation thesis is focused on study of gel polymer electrolytes for electrochemical power sources, but also for other application. The electrical, electrochemical, mechanical and optical properties of gel electrolyte samples were measured in this work. The main goal was to prepare samples with high specific conductivity and with largest possible potential windows. Thermal stability of some samples was also monitored using thermogravimetric analyzes. The optimization of the chemical composition, quantities and ratios of individual chemicals has been made. Comparison of thermal polymerization and UV polymerization was performed. In the first part of the work, aprotic solvents and their mixtures in combination with lithium and sodium salts and one ammonium salt were investigated. Another subject of research was various crosslinking agents with methacrylate-based monomers. The second part of the work investigated the effect of ionic liquids, phosphor base flame retardants and nanoparticles as additives to gel electrolytes. In the last part of the work, the influence of the magnetic and electric field on the polymerization of gel electrolytes containing nanoparticles and selected copolymers was studied. Finally, a Li-ion cell with a graphite anode, LiFePO4 cathode and selected gel electrolyte was assembled.
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Gel polymer electrolytes modified by ionic liquids with aprotic solvents
Pospíšilová, Michaela ; Sedlaříková, Marie (referee) ; Jahn, Michal (advisor)
This graduate thesis is focused on measuring the electrical conductivity of the gel polymeric electrolytes, their preparation and deals with the changes of the performance ratio of the individual substances in gel electrolyte The theoretical part deals with electrochemistry, gel electrolytes, the conductivity of electrolytes, gel electrolytes preparation, methods used to evaluate the measured results and on the properties of the ionic liquids. In the practical part is summarized the process of preparing gel electrolytes, the chemicals to prepare the gels with ionic liquids. The results are evaluated by using impedance technique and linear voltammetry, there are calculated the values of the electrical conductivity of the electrolyte and potential windows.
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Gel polymer electrolytes with nanoparticles
Szotkowski, Radek ; Sedlaříková, Marie (referee) ; Jahn, Michal (advisor)
This master‘s thesis concerns gel polymer electrolytes formed on a methyl methacrylate base with selected types of nanoparticles. In the thesis are also analyzed the methods for measuring electrochemical properties. The practical portion deals with sample preparations of gel polymer electrolytes with different contents of alkaline salt in a solvent, creating gels with different nanoparticle content and comparing gel polymer electrolytes polymerized with heat and UV radiation. The thesis deals with the evaluation of these samples from the viewpoint of electrical conductivity and potential windows as well as thermal analysis of selected samples.
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Polymerization of Lactides in the Melt
Horkel, Ondřej ; Tomala, Libor (referee) ; Petrůj, Jaroslav (advisor)
This bachelor thesis deals with the problematics of Lactide polymerization in the melt. Theoretical part summarizes properties of lactic acid, lactides and polylactides as well as currently used methods of their preparation. In experimental part, a set of three experiments was designed, namely dependance of viscosity average molecular weight on catalyst concentration, polymerisation temperature and polymerisation time. This was achieved by measuring cinematic viscosity using Ubbelohde viscosimeter. As a result of these experiments, it was found that one of posssible combinations of conditions resulting in high molecular weight polymers is the following: concentration ratio of catalyst towards lactide 110–4, polymerisation teperature 160 °C and polymerisation time 3 hours.
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