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Isolation, characterization and application of biomedically important polymer P(3HB-co-4HB)
Krupičková, Kristýna ; Přikryl, Radek (referee) ; Obruča, Stanislav (advisor)
This diploma thesis deals with the isolation and characterization of copolymer P(3HB-co-4HB). The teoretical part was prepared as a literature search which describe polyhydroxyalkanoates in general, their structure, synthesis, degradation and isolation. Furthermore, copolymers containing 4HB units are mentioned in this thesis and there is also no mentioned of the biosynthesis and biodegradation of copolymer P(3HB-co-4HB). The first aim of this diploma thesis was to find out which solvent is the best for copolymer extraction and then characterize obtained copolymer P(3HB-co-4HB). The isolated copolymer was characterized by gas chromatography, SEC-MALS, thermal analysis and SEM. In the second part of the thesis, release of model biologically active substance from the PHA films was studied. Rhodamine 6G dye was selected for the simulation, which was used to stain the copolymer films and the P(3HB) films. It was observed that film prepared from P(3HB-co-4HB) copolymer released entrapped substance much faster than film made from P3HB homopolymer, and, in addition, the copolymer was substantially more susceptible to enzyme degradation.
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Preparation of biodegradable films from PHA copolymers and evaluation of their application potential
Drotárová, Lenka ; Přikryl, Radek (referee) ; Sedláček, Petr (advisor)
This diploma thesis deals with the production of biodegradable PHA copolymer fims and the subsequent study of their material properties. The main goal of this thesis is to assess the application potential of PHA copolymer films in the biomedical industry. The theoretical part of the thesis deals with the characterization of polyhydroxyalkanoates and their copolymers, in terms of physical properties, synthesis, biodegradation or PHA producers. The current research in the processing and use of PHA in biomedicine is described in the literature search. The cultivation of bacterial strains of Aneurinibacillus sp. H1 and Cupriavidus necator H16 was done in the experimental part. Different ratios of glycerol and 1,4-butanediol substrates were used during the cultivation of Aneurinibacillus sp. H1, to obtain copolymers of P(3HB-co-4HB) with a different monomer composition. Polymer films were isolated from the obtained biomass by the extraction method and were characterized by GC-FID, FTIR and SEC-MALS methods. Subsequently, copolymer films containing of 65,25 and 43,61 wt. % 4HB and homopolymer PHB film were selected for release experiments. The drugs, ibuprofen and acetylsalicylic acid, were used for release experiments, their release from the polymer film into the physiological solution was monitored by UV-VIS spectroscopy. Based on the obtained data, the application potential of PHA copolymer films as a carrier system in biomedical use was verified.
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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).
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Optimizing of Polymer Surface Treatment for Microscopic Examination
Horská, Pavlína ; Poláček, Petr (referee) ; Bálková, Radka (advisor)
Supramolecular structure of eight commercial types of iPP, its blends with poly(L-lactide) (PP-PLLA) and copolymers with ethylene-propylene rubber (PP-EPR) together with four types of polyethylene (LDPE, HDPE) was uncovered and observed in this work. The spherulitic structure of iPP and PE homopolymers and PP copolymers was uncovered by etching of six different solutions of mineral acids with KMnO4 and by dissolution in four selected solvents. The latter was found to be ineffective. The structure of PP-PLLA blends was uncovered only after recrystallization (the change of structure by annealing and cooling rate). The uncovered crystalline structure was observed directly by confocal laser scanning microscope (CLSM) and SEM. Crystallinity together with a size distribution of crystallites was determined by DSC. It was proved that spherulitic supramolecular structure was easy to uncover by chemical etching only for molded samples and for fracture surfaces of injected samples. The efficiency of etchants varied but, generally, the samples with high degree of crystallinity were etched earlier. The etchants containing nitric acid and high content of sulphuric acid uncovered fine details of shperulites with respect to mixtures containing orthophosporic acid. It was also observed that not only the etchant (especially with nitric acid) itself but also its vapors were effective. The structure was revealed later but the appearance was plastic (3D) and the structure was very fine. The supramolecular structure of PP-PLLA blends differed with amount of each component. The ethylene-rubber phase came forth with increasing time of etching while PP spherulites disappeared in PP-EPR samples. CLSM was shown to be very good tool for observing supramolecular structure of studied samples with respect to SEM, which was proved to be entirely unsuitable for polyolefines. DSC is recommended to be performe before uncovering supramolecular structure for basic information about proportion of amorphous/crystalline phase and size of crystallites.
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Use of copolymer polyhydroxyalkanoates in development of intelligent packaging
Kreuzerová, Monika ; Kalina, Michal (referee) ; Sedláček, Petr (advisor)
This bachelor thesis deals with the preparation and characterization of copolymers P(3HB-co-4HB). The theoretical part discusses polyhydroxyalcanolates (PHA), where their structure, properties and synthesis are described and subsequently the selected copolymers, which contain monomeric units 3HB, are listed. Furthermore, the review part is processed for the current state of the issue, which states the use of copolymers PHA and current research work on the incorporation of active substances into copolymers. The aim of this work was to characterize and compare the created P(3HB) and P(3HB-co-4HB) foils with a 4HB monomeric unit of 65,25 % and 43,61 % and subsequently determine the potential of foil usability as intelligent packaging materials. First, PHA were subjected to gas chromatography, SEC-MALS, FTIR and DSC analysis. In the second part of the thesis, the permeability of foils to water vapor and the release of model active substances from PHA foils was studied. For this purpose, two active substances (curcumin and salicylic acid) were selected, which were incorporated into a film of homopolymer P(3HB) and two copolymers with a proportion of 4HB of 65,25 % and 43,61 %. In foils prepared from copolymers, the active substances diffusion was faster than in P(3HB). Within the copolymers, P(3HB-co-43,61%4HB) released substances at a higher speed, due to the greater crystallinity of a copolymer containing 65,25 % 4HB.
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Copolymeric Acrylamide Gels: Preparation and Properties
Nováková, Pavlína ; Petruš, Josef (referee) ; Kučera, František (advisor)
The bachelor thesis deals with the preparation and properties of copolymer acrylamide gels. The theoretical part is focused on the general characteristics of gels, closer look at copolymeric acrylamide gels – preparation methods, various possibilities of initiation, crosslinking, and use of comonomers. Factors influencing swelling of the gel were described. The experimental level focuses on the preparation of neutral polyacrylamide gel and acrylamide copolymeric gel with anionic component, sodium acrylate. First, the formation of the copolymer and the presence of functional groups were verified by infrared spectroscopy with Fourier transformation. Then gels of different concentrations of sodium acrylate and the crosslinking agent, bisacrylamide, were prepared by radical solution polymerisation. The influence of the gel composition on the swelling degree in distilled water was investigated on the prepared samples. The selected samples were then swelled in environments of different pH and ionic strengths to assess the influence of the external environment on the swelling degree.
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Study of mechanism and kinetics of hexa-1,5-diene polymerisation catalyzed by phenoxy-imine titanium complex and MAO
Ševčík, Jan ; Cihlář, Jaroslav (referee) ; Hermanová, Soňa (advisor)
This diploma thesis is focused on study of polymerization of hexa-1,5-diene catalyzed by phenoxy-imine titanium dichloride (FI Ti) and methylaluminoxane (MAO) as cocatalyst. Effect of monomer concentration, polymerization temperature and cocatalyst/catalyst ratio on catalytic activity, molecular weights, polydispersities and particularly microstructure of prepared poly(hexa-1,5-diene) was studied. 1H NMR spectroscopy revealed that the poly(hexa-1,5-diene) microstructure contained methylene-1,3-cyclopentane (MCP) as well as vinyl tetramethylene (VTM) units. Kinetics of this polymerization was studied. Finally, copolymer of ethene and hexa-1,5-diene possessing incorporated pendant vinyl group was prepared.
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Production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) employing selected members of the genus Aeromonas
Čeparová, Klára ; Slaninová, Eva (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis deals with the study of polyhydroxyalkanoates (PHA) production by Aeromonas spp. Four bacterial strains were selected for this study: Aeromonas aquatica (DSM 100827), Aeromonas bivalvium (DSM 19111), Aeromonas hydrophila (CCM 7770) and Aeromonas cavernicola (CCM 7641). The presence of phaC gene responsible for PHA synthesis was verified by polymerase chain reaction (PCR). In three of four selected strains (A. aquatica, A. bivalvium, A. hydrophila) the presence of phaC gene was confirmed. Strains A. cavernicola did not contain the phaC gene. PHA synthesis on different carbon substrates was further tested on strains with confirmed presence of the phaC gene. The aim of the thesis was to optimize the cultivation conditions of bacterial cultures for the PHA synthesis. The production of polyhydroxybutyrate (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) P(3HB-co-3HHx) was monitored. The evaluation of polymer presence and concentration in biomass was determined by gas chromatography. For cultivation, decanoic acid, caproic acid, octanoid acid, glukose, sucrose, fructose were used as carbonaceous substrates. The highest of both PHB and the copolymer P(3HB-co-3HHx) were recorded by A. aquatica with addition of decanoid acid at a concentration of 1 g/l to the production medium. Among the sugar substrates, cultivation on sucrose was the most successful with, resulting in the highest biomass concentration.
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Tailoring transport properties of controlled release systems based on polyhydroxyalkanoates.
Apsalikova, Zarina ; Obruča, Stanislav (referee) ; Sedláček, Petr (advisor)
V rámci předložené práci, polyhydroxyalkanoáty s odlišnými monomerními jednotkami, jako 3-hydroxyvalerát, 4-hydroxyvalerát, 4-hydroxyhexanoát, a 5-hydroxyvalerát byly připravovány za využití bakteriálního kmenu Aneurinibacillus (AH30, AFN2) za účelem porovnání transportních vlastnosti nosičů na bázi izolovaných kopolymerů. Na základě výsledku plynové chromatografii (GC-FID) se ukázalo, izoláty jsou schopné produkovat PHA s různým procentuálním zastoupením monomerů. Dále molekulová hmotnost a index polydispezity izolovaných kopolymerů byly analyzovány pomoci SEC-MALS. Samotné nosičové systémy byly připravovány s využitím izolovaných kopolymerů a komerčního poly(3-hydroxyburyrát). Optimizace byla zaměřena na nastavení podmínek pro tvorbu částic, filmu a porézního systému. Zkoumanými podmínkami byly koncentrace roztoku, množství pomocné látky, a proces izolace nosičů. Vytvořené nosičové systémy byly charakterizovány z pohledu jejich schopnosti uvolňovat aktivní látku (ibuprofen) do modelového prostředí (fosfátový pufr). Na základě provedené charakterizaci bylo stanoveno, že transportní vlastnosti jsou ovlivněny strukturou polymeru a interakcemi v systému polymer-rozpouštědlo. Skenovací elektronová mikroskopie, diferenciální skenovací kalorimetrie, infračervená spektroskopie s Fourierovou transformaci a UV-VIS spektroskopie byly využity jako nástroje pro porovnání a pochopení korespondence mezi chemickou strukturou PHA a jejich transportními vlastnostmi.
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Use of copolymer polyhydroxyalkanoates in development of intelligent packaging
Kreuzerová, Monika ; Kalina, Michal (referee) ; Sedláček, Petr (advisor)
This bachelor thesis deals with the preparation and characterization of copolymers P(3HB-co-4HB). The theoretical part discusses polyhydroxyalcanolates (PHA), where their structure, properties and synthesis are described and subsequently the selected copolymers, which contain monomeric units 3HB, are listed. Furthermore, the review part is processed for the current state of the issue, which states the use of copolymers PHA and current research work on the incorporation of active substances into copolymers. The aim of this work was to characterize and compare the created P(3HB) and P(3HB-co-4HB) foils with a 4HB monomeric unit of 65,25 % and 43,61 % and subsequently determine the potential of foil usability as intelligent packaging materials. First, PHA were subjected to gas chromatography, SEC-MALS, FTIR and DSC analysis. In the second part of the thesis, the permeability of foils to water vapor and the release of model active substances from PHA foils was studied. For this purpose, two active substances (curcumin and salicylic acid) were selected, which were incorporated into a film of homopolymer P(3HB) and two copolymers with a proportion of 4HB of 65,25 % and 43,61 %. In foils prepared from copolymers, the active substances diffusion was faster than in P(3HB). Within the copolymers, P(3HB-co-43,61%4HB) released substances at a higher speed, due to the greater crystallinity of a copolymer containing 65,25 % 4HB.
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