|
|
Preparation of Poly(3-hydroxybutyrate) based acrylic monomer
Liška, Marek ; Přikryl, Radek (referee) ; Figalla, Silvestr (advisor)
The main aim of this thesis is to research and prepare acrylic (methacrylic) monomers derived from poly(3-hydroxybutyrate). The monomers were prepared in two-step syntheses. In the first step P3HB was depolymerised with selected alcohols and afterwards, products of those syntheses were used as substrate and mixed with polymethylmethacrylate to produce their methacrylic derivates. The selected alcohols for the alcoholysis were ethanol and ethylene glycol. In total, four substances were prepared. Products of alcoholysis were ethyl-3- hydroxybutyrate, 2-hydroxyethyl-3-hydroxybutyrate and their methacrylic derivates. Significant part of this thesis is aimed towards the analysis of prepared substances and the analysis of reactions. In the process, titrations and instrumental methods, such as gel permeation chromatography (GPC), infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), thermogravimetry (TGA) and differential scanning calorimetry (DSC) were used. This work describes preparation and analysis of polymers prepared from methacrylates from the mentioned syntheses. Cross-linked polymers, because of their low glass-transition temperature are elastomers.
|
|
|
Construction of gears with plastic teeth
Selzer, Tomáš ; Vrbka, Martin (referee) ; Křupka, Jiří (advisor)
The thesis discusses the matter of construction of gear trains using plastic parts in both lubricated and non-lubricated environment, trying to give an overview of an up-to-date information in the process. Nowadays, thanks to several years of development, polymer-based gear systems can be used in many cases as a replacement for metal-based ones. The undeniable advantage of such replacement is mostly the lower production cost and its lower weight, which, together with favorable friction properties of polymer materials, makes a number of technological applications much more effective. The first part is dedicated to listing and defining the typical characteristics of polymer materials, which are essential in the process of designing the gear. The next part focuses on evaluation of the available types of solutions for plastic gear trains construction. The last topic is centered around possible defects and the wear as well as the operation conditions and a real-life application of such plastic gear system. The most notable findings are summed up and commented on in the form a discussion. Thanks to the chosen topic, the bachelor’s thesis adds to a closer understanding of the construction and operation of the plastic gear systems.
|
|
|
Relative humidity effects on the electrical properties of silicone ruber
Pušec, Daniel ; Polsterová, Helena (referee) ; Frk, Martin (advisor)
At the beginning, this master thesis briefly describes the principle of semiconductors. It states their types, methods of operation, fields of use, and it interprets the manner of semiconductor devices’ passivation. Then it introduces silicones, their properties and usage. Later on, this thesis summerize air humidity theory and materiál moisturing including mathematical interpretation. Next chapter is devoted to basics of dielectric materials’ behavior. And finally, the last part of this thesis estimates charakteristics of passivation materiál, Dow Corning HIPEC Q1-9205 silicone rubber.
|
|
|
Effective management of plastic waste
Kostková, Kateřina ; Pavlas, Martin (referee) ; Gregor, Jiří (advisor)
The main content of the submitted diploma thesis is the implementation of analysis of separated plastic waste and examination of the issue of extrusion tests. The practical knowledge is preceded by a search of waste management in the Czech Republic and get acquainted with the issue of polymer materials. The research is about plastic waste management and preparation of polymeric materials for extrusion tests. Theoretical knowledge is then applied in the practical implementation of extrusion tests.
|
|
|
Electrical properties analysis of epoxy resins with various fillers
Horák, Luděk ; Kazelle, Jiří (referee) ; Frk, Martin (advisor)
Presented bachelor thesis is focused on studying electroinsulating epoxy resin-based sealings. It describes the chemical composition, production, properties and measuring methods of basic electric quantities of these materials. This work also embodies a preparation of composite epoxy resin samples with different kinds of micro-ground siliceous sand as a filling. The samples given are measured on the temperature dependency of relative permitivity, dissipation factor and inner resistivity.
|
|
|
Engineering plastics for specific applications
Vrátný, Martin ; Kebrle, Ondřej (referee) ; Kandus, Bohumil (advisor)
This bachelor’s thesis is focused on heat resistance and chemical resistance of plastics. The first part deals with properties and usage of selected plastics. The second part includes description of heat resistance and chemical resistance. Selected plastics are compared in table by their resistance. In conclusion the plastics are compared by detected data and suitability of plastics in environment with higher temperatures and aggresive chemical impacts.
|
|
|
Phase-separated systems biopolymer-lipid
Kubalová, Barbora ; Pekař, Miloslav (referee) ; Mravec, Filip (advisor)
This diploma thesis deals with experimental study of interaction based on polymer-lipid system. The main goal was to investigate interaction leading to phase separation. Three anionic polyelectrolytes were selected for this purpose: sodium hyaluronate, sodium chondroitin-6-sulfate and sodium poly(4-styrenesulfonate). The liposomes were formulated by sonication of lipid – cationic 1,2-dipalmitoyl-3-trimethylamonium-propane (chloride salt) and zwitterionic 1,2-dipalmitoyl-sn-glycero-phosphocholine. It was found that the phase separation occured at specific ratio of DPTAP and selected polymer. It was also explored that the strong electrostatic interaction which leads to the phase separation can be weaken by increasing the ionic strength in the sample. As we aspected the systems contain the hydrophobic domain and therefore these are able to incorporate hydrophobic substances in their structure.
|
|
|
Organic semiconductors and their applications
Galbička, Tomáš ; Sedláček, Jiří (referee) ; Hubálek, Jaromír (advisor)
Bachelor’s thesis is deals with a problem of organic semiconductors, where are describe fundamental principles of charge transport and explanation of basic organic structures. There is described basic operation and layering of simple organic parts especially organic diode. There are practical tests of electrical properties of two different polymer diodes PLEDs. Where in this experimental part are present characteristics of these parts and them comparison at variant ilumination and mutually measuring.
|
|
|
Stents and their applications in medicine
Sokl, Antonín ; Němec, Karel (referee) ; Molliková, Eva (advisor)
The aim of this bachelor thesis, which deals with types of stents and their use in medical area, is the provision od detailed reserches of the most frequently used biomaterials, namely details of metals, ceramics, polymers and composites, considering the suitability of their use for the production of substitutes for particular human body structures. The introductory chapters are devoted to external and internal fixation for fractures, dental implants and replacement of renal function. The following chapters deals with stents and their possible variations, especially the chapters are about esophageal stents, prostatic stents and ureteral stents. The final part of this thesis contains a detailed definition of coronary stents, their functional and shape modifications.
|
|
|
Recyclation of Plastics
Lasota, Ondřej ; Němec, Karel (referee) ; Molliková, Eva (advisor)
Plastic materials thanks to their properties like strength, durability, versatility and relatively low cost has gained this much popularity. With their constantly increasing amounts contribute to the waste. Most frequent method of waste disposal is landfill, which is due to plastic’s durability undesirable and causes serious problem for the environment. This bachelor thesis focuses on the use of secondary raw materials obtained from polymer waste. Large amounts of generated polymer waste can be appropriately designed methods processed to produce fuel, to modify asphalt mix and to reinforce concrete. Different methods are analyzed and their advantages and disadvantages are shown.
|
guest ::
