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Photopolymerization kinetics of dimethacrylate dental resin
Vaněk, Martin ; Bystřický, Zdeněk (referee) ; Poláček, Petr (advisor)
Aim of magister´s thesis was to study reaction kinetics of dental materials. Thesis was focused on dimethacrylate dental polymers, which are for example used for dental restoration, tooth repair and creating now teeth. First part of the thesis concentrates on influence of molar ratio on reation kinetics by addition of other monomer to polymer resin. Second part concentrates on influence of addition of additive silica on reaction kinetics of polymerization. Essential variables know as a polymerization ratio, conversion, gel point, glass transition temperature and storage modulus were studied. Firstly, polymerization ratio and conversion were observed by differential scanning calorimetry (DSC). Secondly rheology was observed by photoreometr. Finally, glass transition temperature and storage modulus were observed by dynamic mechanical analysis (DMA). Behaviour changes caused by addion of monomer or filler point out decrease of polymeration ratio and converstion. Same behaviour was observed by short exposure. In order to established network formation, values of gel point increased by higher concentration of monomer or filler. Glass transition temperature and storage modulus measured by DMA were evaluated. Those valuables had variable tendency due to monomer acting like filler at higher concentration. Also contradictory impact of different material conversion and filler concetration was discussed.
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Determination of propene polymerization kinetics on Ziegler-Natta catalysts by methods of batch and Stopped-Flow polymerization performed under industrial conditions
Tvrdý, Michal ; Merna,, Jan (referee) ; Kratochvíla, Jan (advisor)
This thesis is focused on the determination of the propene polymerization kinetics on phthalate and nonphthalate diester Ziegler-Natta MgCl2-supported catalysts under the industrial conditions. The kinetic profiles were determined by various laboratory techniques for propene polymerization. For assessing the profiles were utilized batch gas and liquid polymerization modes in 2-litre and 4-litre reactors. Finally, the results were complemented with the runs performed in a unique Stopped-Flow apparatus, which allows polymerization of liquid propene at very short polymerization times. The kinetics profiles of both catalysts were determined and compared by combination of experimental data of these techniques. The basic properties of the synthesized polymeric powders were measured, such as the melt flow index, bulk density and amount of polypropene fraction soluble in cold xylene.
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Photopolymerization kinetics of dimethacrylate dental resin
Vaněk, Martin ; Bystřický, Zdeněk (referee) ; Poláček, Petr (advisor)
Aim of magister´s thesis was to study reaction kinetics of dental materials. Thesis was focused on dimethacrylate dental polymers, which are for example used for dental restoration, tooth repair and creating now teeth. First part of the thesis concentrates on influence of molar ratio on reation kinetics by addition of other monomer to polymer resin. Second part concentrates on influence of addition of additive silica on reaction kinetics of polymerization. Essential variables know as a polymerization ratio, conversion, gel point, glass transition temperature and storage modulus were studied. Firstly, polymerization ratio and conversion were observed by differential scanning calorimetry (DSC). Secondly rheology was observed by photoreometr. Finally, glass transition temperature and storage modulus were observed by dynamic mechanical analysis (DMA). Behaviour changes caused by addion of monomer or filler point out decrease of polymeration ratio and converstion. Same behaviour was observed by short exposure. In order to established network formation, values of gel point increased by higher concentration of monomer or filler. Glass transition temperature and storage modulus measured by DMA were evaluated. Those valuables had variable tendency due to monomer acting like filler at higher concentration. Also contradictory impact of different material conversion and filler concetration was discussed.
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|
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Determination of propene polymerization kinetics on Ziegler-Natta catalysts by methods of batch and Stopped-Flow polymerization performed under industrial conditions
Tvrdý, Michal ; Merna,, Jan (referee) ; Kratochvíla, Jan (advisor)
This thesis is focused on the determination of the propene polymerization kinetics on phthalate and nonphthalate diester Ziegler-Natta MgCl2-supported catalysts under the industrial conditions. The kinetic profiles were determined by various laboratory techniques for propene polymerization. For assessing the profiles were utilized batch gas and liquid polymerization modes in 2-litre and 4-litre reactors. Finally, the results were complemented with the runs performed in a unique Stopped-Flow apparatus, which allows polymerization of liquid propene at very short polymerization times. The kinetics profiles of both catalysts were determined and compared by combination of experimental data of these techniques. The basic properties of the synthesized polymeric powders were measured, such as the melt flow index, bulk density and amount of polypropene fraction soluble in cold xylene.
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