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Study of electric properties of nanocomposites
Libra, Miroslav ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
The present master´s thesis deals with the electrical properties of nanocomposite materials. Samples for the experiment are made epoxi resin and oxides TiO2 and Al2O3 as nanofillers in different percent performace. The samples nanocomposites are measured temperature dependence of the resistivity inside, dissipation factor and relative permittivity. It discusses the effect of the filler on the resulting electrical properties of the polymer.
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Epoxy resins exposure under severe climatic conditions
Hanačík, Radim ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This thesis describes the effects of climatic factors, particularly humidity and temperature on the properties of macromolecular substances, but also others, such as UV radiation, wind, water and oxygen. Furthermore, we introduce the definition and distribution of macromolecular substances. The next section describes the basic properties of dielectric materials. Much of the text is devoted to the description, production, curing, properties and utilization of epoxy resins. The last part deals with climate factors in general terms.
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Epoxy resins exposure under severe climatic conditions
Hanačík, Radim ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This thesis describes the effects of climatic factors, particularly humidity and temperature on the properties of macromolecular substances, but also others, such as UV radiation, wind, water and oxygen. Furthermore, we introduce the definition and distribution of macromolecular substances. The next section describes the basic properties of dielectric materials. Much of the text is devoted to the description, production, curing, properties and utilization of epoxy resins. The last part deals with climate factors in general terms.
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Study of electrical properties of nanocomposites
Ovsík, Jiří ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
The present work deals with the electrical properties of nanocomposite materials. Samples for the experiment are made of epoxy resin as a matrix and oxides TiO2, Al2O3, WO3, SiO2 as nanofillers in 0.5 and 1 percent performance. The experimental samples are measured in temperature and frequency dependence of relative permittivity, dissipation factor, rezistivity and are broken down by the influence of filler on the electrical properties of the polymer. Attention is also paid to the mechanical properties of nanocomposites.
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Plasmochemical treatment of natural fibres
Demková, Eva ; Mazánková, Věra (referee) ; Přikryl, Radek (advisor)
This bachelor thesis is focused on plasmochemical surface treatment of natural flax fibres using dielectric barrier discharge and silane coupling agent. Treated fibres were used as reinforcement of composite material with an epoxy matrix. Composite materials were prepared manually, by placing saturated fibres into silicone mold. Mechanical properties of composite materials were determined by bending test, tensile test and dynamic-mechanical analysis (DMA). The presence of a silane coupling agent on the surface of the fibre was detected by EDS analysis. SEM method was also used to determine the effect of plasma on the surface of fibres.
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Pultrusion process optimizing of composites based on epoxy matrix
Ostrezi, Jan ; Bábík, Adam (referee) ; Přikryl, Radek (advisor)
The theoretical part of this bachelor thesis deals with current progress in the field of long fibre reinforenced composites with matrix based on epoxy resins. It also deals with production methods of composite materials, especially pultrusion. The practical part is based on pultrusion process optimizing of composites profiles based on epoxy matrix. Profiles were examined by DMA test to set the glass transition temperature.
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Novel nanocomposite materials for power engineering
Boček, J. ; Matějka, Libor ; Mentlík, V.
The epoxy-POSS nanocomposites were prepared and their electrical/dielectric and thermomechanical properties were determined. The mono- and octa-epoxyfunctionalized POSS (POSS,E1 and POSS,E8) were covalently incorporated in the epoxy network matrix DGEBA- 3,3’-dimethyl-4,4’-diaminocyclohexylmethane (Laromin C260) as pendant units or as polyhedral junctions, respectively. While the POSS junctions are well dispersed in the hybrid network DGEBA-Laromin-POSS,E8, the pendant POSS aggregate to form large crystalline POSS domains.
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Časově závislé mechanické vlastnosti jedné epoxidové komposice
Minster, Jiří ; Hristova, Ju.
The paper presents results of experimental investigation of time-dependent mechanical characteristics of a homogeneous isotropic epoxy composition used either as a construction material or a s the matrix of a particulate or fibre composite. The experimental programme involved short- medium- and long-term creep and relaxation investigations of samples loaded by quasi-static pressure.The Young modulus, relaxation modulus and viscoelastic compliance were defined within active pressure and also delayed recovery. The results can serve to assess influences of some important mechanical and non-mechanical loads (mechanical loading, temperature, physical aging, climate effects)
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