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Preparation of PP composites by grafting using monomer treated filler
Kramerová, Nina ; Žídek, Jan (referee) ; Kučera, František (advisor)
Bachelor thesis is focused on preparation of composite materials with polypropylene matrix. The composites were prepared “in situ” with using Brabender mixer. Homogenization of matrix and filler and grafting of PP with anhydride of itaconic acid treated filler proceed together according to radical mechanism of polymerization. Luperox 101 [2,5-dimethyl-2,5-di(tertbutyl-peroxy)hexane] was used as an initiator of the reaction, the concentration of the initiator was 0.5 wt %, processing temperature 210 °C, 30 rpm. PP-g-IA is a compatibilizer between the matrix and the filler. Glass fibers, calcite and two types of ground wood pulp were used as filler. Two analytical methods were chosen to analyze the efficiency of grafting, acid-base titration and infrared spectroscopy. Assigned conversion of monomer was from 42 to 87 % for various fillers.
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Sol-gel synthesis of a LAS glass ceramics and influence of additives on a phase transformation and crystallization.
Kramerová, Nina ; Opravil, Tomáš (referee) ; Ptáček, Petr (advisor)
This work is focused on Li ceramics and glass-ceramics with low thermal expansion. Composition of these material is based on mineralogical composition of ?-spodumene – Li2O•Al2O3•4SiO2. Sol-gel route of preparation was used for preparation of the material. Sol-gel route is profitable because of production of high purity and controlled grain size powder. Lower sintering temperature, higher degree of homogeneity and shorter time of heat treatment in comparison with traditional approach belong among other advantages of sol-gel route of preparation. Influence of Li+ substitution for K+, which has similar atomic radius, is assessed in this work. These ions are localized in the interstitial position of spodumene structure and are able to maintain the charge balance. Li+ ions were substituted with K+ in the amount of 0; 0,5; 1; 2; 5 and 10 wt. % in view of Li+ weight. In the next step influence of adding mineralizer was specified in the material modified this way. The effect of adding mineralizer on phase transformation and heat treatment tendency was considered. K+ were added to the mixture in the form of potash. Due to this addition forming of orthoclase phase next to spodumene, eucryptit and SiO2 (ss) was detected. Decrease in melting temperature and ability of melt to crystallize were consequence of orthoclase forming. No crystallization appears, when more than 1 wt.% of K+ was added.
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Sol-gel synthesis of a LAS glass ceramics and influence of additives on a phase transformation and crystallization.
Kramerová, Nina ; Opravil, Tomáš (referee) ; Ptáček, Petr (advisor)
This work is focused on Li ceramics and glass-ceramics with low thermal expansion. Composition of these material is based on mineralogical composition of ?-spodumene – Li2O•Al2O3•4SiO2. Sol-gel route of preparation was used for preparation of the material. Sol-gel route is profitable because of production of high purity and controlled grain size powder. Lower sintering temperature, higher degree of homogeneity and shorter time of heat treatment in comparison with traditional approach belong among other advantages of sol-gel route of preparation. Influence of Li+ substitution for K+, which has similar atomic radius, is assessed in this work. These ions are localized in the interstitial position of spodumene structure and are able to maintain the charge balance. Li+ ions were substituted with K+ in the amount of 0; 0,5; 1; 2; 5 and 10 wt. % in view of Li+ weight. In the next step influence of adding mineralizer was specified in the material modified this way. The effect of adding mineralizer on phase transformation and heat treatment tendency was considered. K+ were added to the mixture in the form of potash. Due to this addition forming of orthoclase phase next to spodumene, eucryptit and SiO2 (ss) was detected. Decrease in melting temperature and ability of melt to crystallize were consequence of orthoclase forming. No crystallization appears, when more than 1 wt.% of K+ was added.
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Preparation of PP composites by grafting using monomer treated filler
Kramerová, Nina ; Žídek, Jan (referee) ; Kučera, František (advisor)
Bachelor thesis is focused on preparation of composite materials with polypropylene matrix. The composites were prepared “in situ” with using Brabender mixer. Homogenization of matrix and filler and grafting of PP with anhydride of itaconic acid treated filler proceed together according to radical mechanism of polymerization. Luperox 101 [2,5-dimethyl-2,5-di(tertbutyl-peroxy)hexane] was used as an initiator of the reaction, the concentration of the initiator was 0.5 wt %, processing temperature 210 °C, 30 rpm. PP-g-IA is a compatibilizer between the matrix and the filler. Glass fibers, calcite and two types of ground wood pulp were used as filler. Two analytical methods were chosen to analyze the efficiency of grafting, acid-base titration and infrared spectroscopy. Assigned conversion of monomer was from 42 to 87 % for various fillers.
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