National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Inflence of technological conditions and polyhydroxybutyrate materials composition on crystallinity
Olšan, Jakub ; Petruš, Josef (referee) ; Kučera, František (advisor)
Diploma thesis is summarizing sources and technology of PHB and its physical and chemical properties compared to other polymers. Thesis mentions usage and function of certain additives in PHB matrix and their impact on the final product. Practical part of the thesis is concerned with technological parameters and degradation of the PHB during extrusion. The thesis also observes behaviour of nucleating agents on crystallinity and crystallization properties of prepared compounds. Degradation was analyzed by MFI and colour difference against standard material, FTIR was not successfully used for the purpose of degradation. Crystallinity and crystallization behaviour was analysed by DSC and optical microscopy with heated operating table. Graphs were created from results of analysis and suitable usage of each nucleating agent was considered. Boron nitride was selected as the most suitable nucleating agent due to creating higher amount of smaller spherulites.
PP/PA6 polymer blend preparation
Olšan, Jakub ; Petruš, Josef (referee) ; Kučera, František (advisor)
Bachelor’s thesis studies preparation of polymer blends of polyamide 6 with polypropylene. A present knowledge about preparation of polymer blend of PA6/PP was summarized in theoretical part. Experimental part is focused on an ideal ratio of starting materials for compounding to get maximal elongation at break. At first the preparation of samples was realised in Brabender mixer at temperature of 240 °C, reaction time 6 minutes and 50 RPM. Later, samples were prepared in double-screw extruder at temperature zones between 220 and 240 °C, transition time 3,5 minutes and 90 RPM. All samples were measured on melt flow rate and tensile test. Morfology was studied by SEM. Due to SEM it was discovered that there is huge difference between compatibilized and uncompatibilized blends in their morfology. Thanks to FTIR and DSC it was proved that there is chemical bond between PA 6 and compatibilizer. Conditionation of this exact blend was done to discover the influence on mechanical properties.

See also: similar author names
2 Olšan, Jan
5 Olšan, Jiří
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