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Pultrusion process of composite based on flax fibres
Hahn, Filip ; Poláček, Petr (referee) ; Přikryl, Radek (advisor)
Theoretical part of master's thesis is focused on chemical treatments of natural fibers and their use as reinforcement material in polymer composites. Flax fibers were treated with two different silane coupling agents to improve their adhesion with polymer matrix. Nature of treatment was studied by using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Composites based on both treated and untreated flax fibers were prepared by pultrusion.technique. Mechanical properties and water absorption of prepared composites were evaluated.
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Properties of nanocomposite based on PHB and HNT
Stehnová, Ivana ; Pavliňáková, Veronika (referee) ; Přikryl, Radek (advisor)
This bachelor’s thesis deals with nanocomposite containing polyhydroxybutyrate matrix filled with halloysite nanotubes. It summarizes findings about optimization of surface modification of the filler, compatibility between the filler and polymer, distribution of the filler in the composite and effect of the filler surface modification, the composite preparation and the filler content on mechanical properties of the composite. Surface modification of the filler was done using 3-(trimethoxysilyl)propylmethacrylate. Efficiency of the silanization was verified by thermogravimetric analysis and Raman spectroscopy. Concentrates containing the unmodified and the modified nanofiller in poly(vinylacetate) or poly(3-hydroxybutyrate) were prepared. Using these concentrates, composites containing 1 % and 3 % of the filler were prepared. Distribution of the filler in the concentrates and the composites and compatibility between the filler and polymer were observed by scanning electron microscopy. Mechanical properties of the composites were tested by tensile test.
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Application and properties of silicone textile coatings
Bernátová, Silvia ; Petruš, Josef (referee) ; Kučera, František (advisor)
The diploma thesis in the first part deals with a theoretical description of coating technologies, textile materials used in coatings, types of coated polymers and properties of coatings - especially adhesion. The experimental part of the work is devoted to the preparation of textile coatings from polyester fabric and coating based on addition silicone. Using the developed method of sample preparation for T-peel testing of the adhesive strength, the improvement of the adhesion of the coating by chemical adhesion with the support of adhesive agents was studied. The second method studied the change in compactness and adhesion of the coating to the fabric after shaking as a function of breathability. The influence of side reactions of reagents on silicone cohesion was studied by preparing dogbones for testing tensile-deformation properties. The research also included the characterization of silicone samples using ATR-FTIR, monitoring the weight gain and thickness of the fabric after coating, the feel and color stability of the applied fabric and observing the coating under an optical microscope.
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Application and properties of silicone textile coatings
Bernátová, Silvia ; Petruš, Josef (referee) ; Kučera, František (advisor)
The diploma thesis in the first part deals with a theoretical description of coating technologies, textile materials used in coatings, types of coated polymers and properties of coatings - especially adhesion. The experimental part of the work is devoted to the preparation of textile coatings from polyester fabric and coating based on addition silicone. Using the developed method of sample preparation for T-peel testing of the adhesive strength, the improvement of the adhesion of the coating by chemical adhesion with the support of adhesive agents was studied. The second method studied the change in compactness and adhesion of the coating to the fabric after shaking as a function of breathability. The influence of side reactions of reagents on silicone cohesion was studied by preparing dogbones for testing tensile-deformation properties. The research also included the characterization of silicone samples using ATR-FTIR, monitoring the weight gain and thickness of the fabric after coating, the feel and color stability of the applied fabric and observing the coating under an optical microscope.
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Properties of nanocomposite based on PHB and HNT
Stehnová, Ivana ; Pavliňáková, Veronika (referee) ; Přikryl, Radek (advisor)
This bachelor’s thesis deals with nanocomposite containing polyhydroxybutyrate matrix filled with halloysite nanotubes. It summarizes findings about optimization of surface modification of the filler, compatibility between the filler and polymer, distribution of the filler in the composite and effect of the filler surface modification, the composite preparation and the filler content on mechanical properties of the composite. Surface modification of the filler was done using 3-(trimethoxysilyl)propylmethacrylate. Efficiency of the silanization was verified by thermogravimetric analysis and Raman spectroscopy. Concentrates containing the unmodified and the modified nanofiller in poly(vinylacetate) or poly(3-hydroxybutyrate) were prepared. Using these concentrates, composites containing 1 % and 3 % of the filler were prepared. Distribution of the filler in the concentrates and the composites and compatibility between the filler and polymer were observed by scanning electron microscopy. Mechanical properties of the composites were tested by tensile test.
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Pultrusion process of composite based on flax fibres
Hahn, Filip ; Poláček, Petr (referee) ; Přikryl, Radek (advisor)
Theoretical part of master's thesis is focused on chemical treatments of natural fibers and their use as reinforcement material in polymer composites. Flax fibers were treated with two different silane coupling agents to improve their adhesion with polymer matrix. Nature of treatment was studied by using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Composites based on both treated and untreated flax fibers were prepared by pultrusion.technique. Mechanical properties and water absorption of prepared composites were evaluated.
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Development of silane modified TS-1 nanoparticles as fillers for Mixed Matrix Membranes (MMM’s)
Martin-Gil, V. ; Lhotka, M. ; Hrabánek, Pavel ; Fíla, V.
In this work, Titanium Silicalite 1 (TS-1) was synthesized using different crystallization temperature (Tc = 180 °C, 160°C, 140°C), aging time (t aging = 1, 2, 3 and 7 days) and aging temperature (T aging = T room , 40 °C, 80°C) in order to get suitable nanoparticle size and good distribution of particle size for using them as a filler in MMMs. The TS-1 particles with different Si/Ti ratios (Si/Ti = 25 and 100) were functionalized using different amino silane coupling agents: 3-aminopropyltriethoxysilane (APTES), 3- aminopropyltrimethoxysilane (APTMS) and 3-aminopropylmethyldiethoxysilane (APMDES). Moreover, a new kind of silane coupling agents: 3- glycidoxypropyltriethoxysilane (GPTES), 3-glycidoxypropyltrimethoxysilane (GPTMS) and 3-glycidoxymethyldiethoxysilane (GPMDES) were also used. Tetrahydrofuran (THF), with a high dielectric constant (7.6), was used as solvent in order to control the surface modification and avoid pore blockage. The samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), as well as carbon dioxide methane and nitrogen adsorption measurements. The obtained results showed that aging temperature at long aging times have the main effect on the morphology of the particles meanwhile crystallization temperature influences gas adsorption properties. T aging higher than T room showed a great influence on the particle size at t aging = 7 days; shorter t aging did not show an observable influence on the particle size. Crystallization temperature influences the adsorption properties; at lower crystallization temperature, higher quantity of CO 2 adsorbed and lower quantity of CH 4 adsorbed. At last, suitable TS-1 filler with good size distribution and particle size about 200nm was obtained using Si/Ti = 100 and Si/Ti = 25, T c = 140 °C, T aging = 40 °C and t aging = 7 days.
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