Structural analysis of polyaniline-polyprrole copolmers via pyrolysis mass spectrometry

Tezal, Feride
This thesis describes recent progress in electrochemical preparation of several conducting polymers. In particular, the synthesis and characterizations of pure polyaniline, pure polypyrrole, polyaniline/polypyrrole and polypyrrole/polyaniline copolymers and polyaniline-polypyrrole physical blends were studied. The focus has included firstly synthesis of these electrically conductive polymers. Secondly, thermal characteristics of electrochemically synthesized homopoly- mers, copolymers and their physical blends were investigated by thermal gravi- metric analysis (TGA), differential scanning calorimetry (DSC) and direct pyrol- ysis mass spectrometry (DIP-MS) techniques. In general, TGA analysis showed three-step thermal degradation. The first, at 100oC, was attributed to water, and unreacted monomers. The second weight losses observed at around 150 oC was because of evolution of water and/or acid. Finally, the removal of the dopant ion and low molecular weight species from the matrix were observed for pure PANI and pure PPy at 230 and 280 oC, respectively. PANI/PPy films and PPy/PANI films have decomposition temperatures at 272oC because of the loss of the dopant ion. It was also observed that pure PPy was thermally more resistant than pure PANI. Thirdly, thermal characteristics, and degradation products of electrochemi- cally prepared PANI/PPy and PPy/PANI films in solutions containing variable dopant (SO42) concentrations were analyzed and compared with pyrolysis mass spectrometry. Similar to TGA study, there were three main thermal degradation steps namely, evolution of low molecular weight species, dopant based products and degradation products of polymers. The dopant concentration was monitored to optimize the degradation behavior. Pyrolysis mass spectrometry data showed that the degree of degradation of the polymer already coated on the electrode enhanced as the dopant concentration used in synthesis increased.


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This thesis presents the development of new acyl anion precursors and their applications. The main concern of this thesis was to make use of acyl anion precursors in catalytic bond forming reactions. Toward this aim, previously known cyanide ion catalyzed cleavage of benzils was investigated in scope and efficiency in unsymmetrical benzoin condensation. Although benzils were proved to be useful entities as acyl anion precursors in benzoin condensation, they suffer some major drawbacks. Therefore acylphospho...
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Türkmen, Yunus Emre; Tanyeli, Cihangir; Department of Chemistry (2006)
Optically active polychlorinated bicyclic systems are important starting materials for the synthesis of complex target molecules. In the first part of the study, the syntheses of several racemic and meso hexachloronorbornene derivatives were executed successfully, starting from hexachlorocyclopentadiene. The enantio-enriched acetoxymethyl derivative (-)-2 and the hemiester (-)-6 were synthesized in high e.e. values by using several hydrolase type enzymes. The absolute configuration of (-)-2 was determined b...
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In this thesis, carbon supported platinum nanoparticle catalysts were prepared using PtCl4 and H2PtCl6 as starting materials and 1-heptanethiol, tert-nonyl mercaptan, 1-hexadecanethiol, 1-octadecanethiol as surfactants. These new catalysts were employed for methanol oxidation reaction which are used for direct methanol fuel cells. Tert-nonyl mercaptane was used for the first time in this type of reaction and the other surfactants were used for comparison of the catalysts performance. Cyclic voltammetry (CV)...
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Şardan, Melis; Tanyeli, Cihangir; Department of Chemistry (2010)
The major subject of this thesis is the synthesis of enantiomerically enriched gamma and delta lactones via Ring Closing Metathesis (RCM). Furan and thiophene substituted aldehydes were transformed to the corresponding heteroaryl substituted allylic and homoallylic alcohols by using vinyl and allylmagnesium bromide, respectively and then resultant racemic alcohols were resolved by hydrolase type enzymes (PSC-II, Lipozyme, CAL-B) with high enantiomeric excess values. Since the absolute configuration of alcoh...
Citation Formats
F. Tezal, “Structural analysis of polyaniline-polyprrole copolmers via pyrolysis mass spectrometry,” M.S. - Master of Science, Middle East Technical University, 2007.