National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Effect of catalystic system on the structure of E/P copolymers
Kolomazník, Vít ; Kratochvíla,, Jan (referee) ; CSc, Zdeněk Buráň, (advisor)
Thesis is focused on structural study of ethylene-propylene copolymers (E/P copolymers) produced by gas phase polymerization. Goal of work was to determine the effect of used catalysts on the distribution of ethylene units in the resulting material. Three E/P copolymers were prepared on commercial Ziegler Natta catalysts with diether or phthalate based internal donors. The copolymers were fractionated according crystallization ability and molar mass. Next, the mass content and the distribution of the ethylene units in the copolymer were determined in each fraction by nuclear magnetic resonance (NMR). Together with other structural analytical methods, phthalate internal donor has been found to produce ethylene blocks under certain conditions, while the diether ID lacks this ability.
Preparation and characterization of poly-3-hydroxybutyrate copolymers
Kolomazník, Vít ; Kupka, Vojtěch (referee) ; Porubský, Tomáš (advisor)
This thesis evaluates the synthesis of copolymers based on poly-3-hydroxybutyrate (PHB). The goal is to create a material with the highest possible concetration of PHB with the smallest possible volume of crystal phase. PHB with lower molecular weight and hydroxyl end groups used for polyurethane synthesis was prepared by alcoholysis of PHB polymer with 1,4 butanediol. Polyethylene glycole (PEG) of various molar mass and ratio values was chosen in this thesis as a second reacting substance. Another substance used for copolymeration with PHB was the poly(butylene adipate-co-terephthalate) PBAT. Both variants used hexamethylenediisocyanate (HDI) as a non-toxic bonding agent. From these substances, a block copolymers comprised of soft and hard segments were formed. Hard segments are a result of PHB and it‘s crystalic structure. Soft segmets are comprised of PEG or PBAT macromolecules. The influence of soft segments of various length and molar ratio of reactants on overal polyurethane properties was evaluated. Prepared materials were charactrerized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and infrared spectroscopy (FTIR). Molecular weight was measured by gel permeation chromatography (GPC).

See also: similar author names
2 Kolomazník, Vojtěch
Interested in being notified about new results for this query?
Subscribe to the RSS feed.