National Repository of Grey Literature 20 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Degradation of epoxy resins vith various aditives by solar radiation
Škarabelová, Lenka ; Novák, Vítězslav (referee) ; Kazelle, Jiří (advisor)
This master’s thesis is focused on the study of chemical and physical properties of dielectric materials with main focus on epoxy resins. It includes possible processes that can influence the properties of epoxy resins, both processes that improve polymer properties and processes that cause material degradation. Next part of the thesis is a description of diagnostic methods suitable for measurement of basic electrical quantities of material and design of a suitable method for measuring properties of epoxy resins with different additives, influencing the samples by solar radiation. At the end, the work includes an experiment dedicated to the degradation of epoxy resins with various additives by solar radiation and the evaluation of the experiment.
Properties of pultruded composites based on epoxy matrix
Huljak, Pavel ; Bálková, Radka (referee) ; Přikryl, Radek (advisor)
The theoretical part of this bachelor thesis deals with research of composite materials, especially based on polymer epoxy and polyester resins, using as reinforcement a glass fiber bundles. The practical section includes the production of composite materials and their components along with the most important testing methods. The main goal of the experimental part is to characterize the optimal conditions pultrusion production of epoxy composite material. Another point is characterization of mechanical and chemical properties of the produced composite at a number of test methods. Finally the optimized epoxy composite materials are compared with composites based on polyester resins.
Dielectric properties of epoxy resins
Matoušová, Klára ; Novák, Vítězslav (referee) ; Kazelle, Jiří (advisor)
This diploma thesis deals with the fundamental properties of epoxide mixtures, as determining of these fundamental properties of epoxide mixtures could in the case of favorable results lead to diminishing the amount of defects in epoxide-embedded instrument transformers. As the influence of effects in the manufacturing process of transformers causing poor quality is very extensit, the biggest emphasis is laid capitally on the influence of the epoxide casting mixture composition. The thesis describes the manufacture technology including used methodics and materials. The compositions of epoxide resins and the mechanisms of their curing. Also, the definitions of fundamental properties of dielectric materials and the description of diagnostic methods used to relative permitivity, dissipation factor and inner resistivity are included. suitable casts of acquired samples were set and dried out within the experimental part, followed by measurement of fundamental electrical properties in temperature and frequency relations. Hereafter a comparison of individual samples and the evaluation of their electrical properties will be carried out.
Production technology for a vacuum mold
Ponka, Ondřej ; Bartoš, Tomáš (referee) ; Zemčík, Oskar (advisor)
The master thesis deals with the design and production of the mold for vacuum forming. Specifically, how the existing and new mold materials affect their design and, consequently, their production technology. The thesis contains a brief description of the principle of vacuum molding. Technological and design principles of designing molds. Furthermore, the realization of the solution variants and the simulation of their production. The solved variants are subsequently evaluated from a technical and economic point of view.
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.
Polymer matrix based on epoxydized oils
Kvasničková, Lucie ; Tocháček, Jiří (referee) ; Přikryl, Radek (advisor)
The theoretical part of this bachelor thesis deals with a current state in the field polymer matrix based on vegetable oils and their epoxidation. Subsequently it deals with epoxy resins – particularly their structure, crosslinking and a curing. The experimental part of this research focuses on the amine curing of epoxy resins. A curing of epoxidized soybean oil with various amine curing agents was tested and also a curing of a blend containing comercial epoxy resin and epoxidized soybean oil. Testing pieces were prepared from selected mixtures and a tensile test was performed on them.
Polymers based on epoxydized oils
Zálešáková, Romana ; Tocháček, Jiří (referee) ; Přikryl, Radek (advisor)
The aim of the bachelor’s thesis is study of materials based on epoxidized vegetables oils, production of test specimens of selected matrix and assessment of its mechanical and thermal properties. The theoretical part deals with epoxy resins, their structure and curing. Then it deals with general description of vegetable oils and their epoxidization. Experimental part describes curing of epoxy resin by hardeners, based on carboxylic acid anhydrides. Curing epoxidized soybean oil was tested with different anhydride hardeners and curing the mixture with commercial epoxy system. Test specimens were prepared from selected mixtures. Specimens were studied by tensile, bending and impact test, TGA and DMA.
Study of properties of nanocomposites
Hudec, Jiří ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
This masters’s thesis study electric properties of nanocomposites based on epoxy resins, production of samples and measuring their electrical properties. In this thesis there are observed temperature dependences of the dissipation factor, relative permittivity and internal resistivity.
Electric properties of composite materials with microparticles and nanoparticles
Dvořák, Tomáš ; Polsterová, Helena (referee) ; Hudec, Jiří (advisor)
This thesis study and compare electric properties of micro and nanocomposites based on epoxy resins depending on temperature. In this thesis are observed temperature dependences of the dissipation factor, relative permittivity and internal resistivity.
Electrical properties analysis of epoxy resins with different fillers in temperature and frequency dependence
Horák, Luděk ; Novák, Vítězslav (referee) ; Kazelle, Jiří (advisor)
Presented master's 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. The aim of the thesis is to compare several sets of samples of composite epoxy resins with different kinds of micro-ground siliceous sand as a filling. The temperature and frequency dependence of relative permittivity, dissipation factor and inner resistivity are measured for given samples.

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