Presented diploma thesis deals with the study of ring-opening polymerization (ROP) of caprolactone catalyzed by novel organic and organometallic compounds. In the theoretical part of the thesis a summary of polymerization strategies and catalytic/initiators systems for ROP of polyesters is overviewed on the basis of reported background research. In experimental part a series of caprolactone polymerization runs with the view of polymerization conditions (solution/monomer ratio, catalyst/initiator ratio, monomer/initiator ratio and monomer concentration) at the temperature range of 25-70 °C was carried out. The experimental study was focused on catalytic precursors based on organic carbenes (tBuNCH=CHN+tBu)CH Cl- (NHC-tBu) in tetrahydrofuran solution and complex of aluminium{O,O’-[4,5-P(O)Ph2tz]-AlMe2} Ph = phenyl, tz = triazole, (OAlMe2) in chlorobenzene solution. Obtained polymers were precisely characterized by means of 1H NMR spectroscopy (Bruker Avance), Differential scanning calorimetry (TA Instruments Q 2000) and Gel permeation chromatography (Agilent Technologies 1100 series) methods. The microbial degradability of synthesized polymer sample having Mn = 12 kg/mol, Mw/Mn = 2.5 and crystallinity degree of 53 % was examined. The polymer in the form of melt-pressed films and powder form was bacterially aged in Bacillus subtilis (BS) strain inoculated mineral and nutrient media for 42 days. Scanning electron microscopy (SEM) and Confocal laser scanning microscopy (CLSM) confirmed the crack development on the surface of films as the consequence of microbial attack in comparison with unchanged control samples. Moreover, the pink coloration of polymer suspension was observed as the consequence of bacterial activity.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:216644 |
| Date | January 2010 |
| Creators | Boháčová, Zdeňka |
| Contributors | Vojtová, Lucy, Hermanová, Soňa |
| Publisher | Vysoké učení technické v Brně. Fakulta chemická |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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