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Stabilizing epoxide systems in surface protective varnishes
Švardala, Daniel ; Tocháček, Jiří (referee) ; Petruš, Josef (advisor)
The diploma thesis describes the influence of humid conditions on the curing of epoxy resins by multifunctional amines. The aim of the experimental part was the identification of degradation products and their quantification, as well as the determination of the influence of humid conditions on the degree of hardening, modulus of elasticity, and flexural strength. Another goal was to optimize the formulation of the reactive mixture for the preparation of epoxy resin with lower susceptibility to carbamate bloom. The degradation products were evaluated by determining the mechanical properties by bending test according to the standard ČSN EN 179-1. The degree of hardening was monitored through temperature modulated differential scanning calorimetry (TMDSC). Degradation products were identified by Fourier transform infrared spectroscopy (FTIR) and quantified by UV-VIS spectroscopy. The morphology of the surface layer was monitored by confocal laser scanning microscopy (CLSM). The dependence of the relative humidity of the environment on the curing process of the epoxy resin and its resulting mechanical properties was determined. Based on the analyzes, a modification of the formulation for the suppression of spurious carbamate during the curing of the epoxy matrix was designed and experimentally verified.
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Study Of Dielectric Behavior Of Polymers Using A Complex Electric Modulus
Horák, Luděk
The complex electric modulus is mathematically defined as the inverse value of thecomplex permittivity. It is particularly useful in evaluating the dielectric properties of polymericinsulating materials, especially at low frequencies and at high temperatures. Presented thesis isfocused on mathematical interpretation, practical example and evaluation of electrical module.In our case, the measurements are performed on a composite material based on epoxy resin.
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Technology of pouring LED strips with epoxy materials
Rudy, Veronika ; Krejčí, Miroslav (referee) ; Píška, Miroslav (advisor)
The thesis deals with the pouring of epoxy materials over LED strips. The research part contains an introduction to photometry and summarizes the types of potting compounds along with their characteristics. The practical part delves into the effect different amount of pigment has on the photometric properties. This is assessed based on verified measurements performed with the help of a goniophotometer on samples with different amounts of pigment, which were created using an integration sphere. Furthermore, a brightness analysis and a long-term outdoor test were performed.
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Development of new chemically resistant coating system containing secondary raw materials
Stodolovská, Šárka ; Jakubík, Aleš (referee) ; Drochytka, Rostislav (advisor)
New types of highly chemically resistant coating systems, primarily designed for concrete and metal substrates are designed and experimentally verified within the diploma thesis. Secondary raw materials, including solidified hazardous waste, are used as microfillers. The developed coating system is solved in two quality levels – PREMIUM and ECOLOGY. The level of PREMIUM is mainly designed for environments where extreme chemical stress is occurring. The polymer coating systém ECOLOGY can be used in environments where aggressive chemical media also act, however the ecological foot of the input raw materials is most important. The diploma thesis is dealing with current issues in the practice and it is the part of the research project.
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Electrical Properties Analysis Of Epoxy Resins With Various Fillers
Horák, Luděk
Presented thesis is focused on studying electroinsulating epoxy resin-based sealings. It describes 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 and dissipation factor.
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Design of vapor proof protective coating for concrete with chemical resistance
Fousková, Marika ; Hodná, Jana (referee) ; Drochytka, Rostislav (advisor)
The main content of the bachelor's thesis is to design a vapor-tight chemically resistant coating using secondary raw materials. Coatings are applied primarily for the purpose of protecting concrete structures that are exposed to chemical stress. Secondary raw materials are used in the coating in the form of a microfiller, which is evenly dispersed in the polymer matrix. The proposed coatings show high adhesion to concrete, excellent workability and applicability, while the filler in the form of secondary raw materials does not impair the properties of the coating, both in fresh and polymerized state.
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Conservation of glass mosaics in epoxy bedding
Viková, Barbora ; Vojtěchovský, Jan ; Hampl, Petr ; Svoboda, David ; Kučerová, Irena
The procedure focuses on the conservation of glass mosaics from the second half of the 20th century, which were embedded into epoxy resin as part of the original technology. The advantage was to create light, easily transportable structures (panels). Various materials were used for the base of these panels, such as steel reinforcement, aluminium plates, but also chipboard plates. Over time, the epoxy bedding proved to be unstable, especially in outdoor conditions, where it often degraded or completely disintegrated. It was therefore necessary to consider replacing the original bedding material with a new one. The replacement of the support is illustrated in the conservation of three mosaics, namely a glass mosaic with chipped tesserae, which is an example of an epoxy-coated mosaic with an embedded metal structure, and two mosaic of crumpled tesserae representing a mosaic glued with an epoxy resin to the chipboard. For both types of mosaics a brand new, more stable mosaic embedding system has been developed.
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DEVELOPMENT OF SPECIAL REHABILITATION MATERIALS FOR CONCRETE FOR EXTREME STRESS WITH USE OF SECONDARY RAW MATERIALS
Hodul, Jakub ; Klečka,, Tomáš (referee) ; Ďurica,, Tibor (referee) ; Bydžovský, Jiří (referee) ; Drochytka, Rostislav (advisor)
The doctoral thesis deals with finding the use of some waste and secondary raw materials in the production of special polymer remediation materials for concrete, which could be applied even in constructions, where extreme mechanical and chemical load is occurred. The aim of this doctoral thesis is experimental examination of the possibility of using selected types of waste, including hazardous waste which represent the highest risk to environment, and secondary raw materials as a substitute for the currently used primary fillers in order to reduce the ecological footprint of the product itself. Some types of secondary raw materials, such as filter fly ash contaminated by flue gas denitrification process, are no longer used as a concrete admixture or partial cement substitution due to unwanted release of toxic ammonia (NH3). Mainly for this reason, the thesis deals with the progressive utilization of such types of secondary raw materials as well as with another currently unused waste into polymeric patching, grouting and anchoring materials while preserving or improving the final properties compared to reference materials using only primary raw materials. The result of this thesis is to find out suitable formulations for efficient preparation of special polymeric remediation materials for concrete containing waste and secondary raw materials as fillers. The partial aim of the thesis and a the scientific contribution is an observation of the developed materials internal structure using a modern device, CT tomography, an influence of the filler type on the long-term durability, and last but not least the observation of the rate of pollutants incorporation, found in hazardous waste, into the polymeric matric with the aid of EDX and FTIR analysis.
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Preparation of Epoxy Based Insulating Materials Filled by Nanoparticles
Mockovčiak, Kristian ; Čech, Ondřej (referee) ; Chladil, Ladislav (advisor)
The present thesis deals with the preparation of epoxy insulating materials filled with nanoparticles and its electrical properties. Experimental samples are made of epoxy resin as a matrix and titanium dioxide nanoparticles (TiO2) as nanofillers in 0.5, 1 and 3 percent filling. Temperature dependencies of internal resistivity, relative permittivity and loss factor are measured on nanocomposite samples. The influence of the filler on the resulting electrical properties of the polymer used is discussed.
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Crystallization of coating systems based on epoxy resins.
Seidlová, Michaela ; Dohnálek,, Pavel (referee) ; Petránek, Vít (referee) ; Drochytka, Rostislav (referee) ; Bydžovský, Jiří (advisor)
Crystallisation of epoxy resins based on bisphenol A and bisphenol F is the natural property of these oligomers. However, manufacturers of paints and other systems based on these epoxy resins, strive to slow down the crystallisation process as much as possible, thereby prolonging the shelf life and improving the competitiveness of their products. The main aim of the thesis is generalisation of the factors influencing the crystallisation process of epoxy resins based on bisphenol A and bisphenol F, verifying new approaches to the possibility of influencing the crystallisation process and determining the possibility of using a certain degree of epoxy resins crystallinity based on bisphenol A and bisphenol F in the preparation and production of epoxy resinbased coating systems.
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