2,3-Dihydro-5-(10-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)anthracen-9-yl)thieno [3,4-b][1,4]dioxine (DTAT) was synthesized via linking 3,4-ethylenedioxy thiophene (EDOT) on anthracene by Stille coupling. Homopolymer P(DTAT) was achieved by electrochemical techniques. The polymer, P(DTAT) was electrosynthesized by anodic oxidation of the corresponding monomer in the presence of 0.1 M LiClO4 as the supporting electrolyte in acetonitrile (ACN) solution. Copolymer of DTAT in the presence of EDOT was synthesized via potentiodynamic method in ACN/LiClO4 (0.1 M) solvent-electrolyte couple. Structural characterizations of the sample was carried out via 1H-Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Electrochemical behaviors of the monomer and polymers were determined by Cyclic Voltammetry (CV). Electrochromic and spectroelectrochemical behavior of the polymers were investigated on ITO glass electrode, and their ability of employment in device construction was examined. Spectroelectrochemistry analysis of P(DTAT) revealed an electronic transition at 505 nm corresponding to &amp / #960 / -&amp / #960 / * transition with a band gap of 1.57 eV. In order to investigate electronic structure of the copolymers obtained by different applied potentials, spectroelectrochemistry studies were performed. Electrochromic investigations showed that P(DTAT) switches between yellow and blue while P(DTAT-co-EDOT) was found to be multichromic, switching between claret red neutral state, a gray and a red intermediate state, and a blue oxidized state. Switching time of the polymers was evaluated by a kinetic study upon measuring the percent transmittance (%T) at the maximum contrast point. Dual type polymer electrochromic devices (ECDs) based on P(DTAT-co-EDOT) with poly(3,4-ethylenedioxythiophene) (PEDOT) were constructed. Spectroelectrochemistry and electrochromic switching of the device was studied. They were found to have good switching times and reasonable contrasts.

In the first part of this dissertation, poly(methylsilyne) was produced both in small and large-scales. In the small-scale, the aim was to synthesize the polymer by electrochemical polymerization of methyltrichlorosilane at a constant potential of -6 V supplied by batteries, using sodium dodecyl sulfate (SDS) as the supporting electrolyte. The polymer was characterized by 1H-NMR, FTIR, UV-Visible Spectroscopy and GPC in addition to its distinctive yellow color. The yellow color and the 1H-NMR, FTIR, UV-Visible and GPC results proved that poly(methylsilyne) was produced successfully in small-scale. In the second part of the synthesis, the objective was to scale-up the electrochemical synthesis of poly(methylsilyne) while investigating the effects of the parameters like the electrode, solvent and supporting electrolyte types, monomer/solvent ratio and reaction time on the synthesis. Although successful results were obtained in large-scale synthesis with acetonitrile and SDS, the problems with the reproducibility of the synthesis were solved using a system containing 1.2-dimethoxyethane (DME) and tetrabutylammonium perchlorate (TBAP). In the second part of the dissertation, the aim was to prepare polypropylene/silicon-based preceramic polymer blends and to characterize them in terms of flammability, thermal and mechanical properties and morphologies. In order to investigate the effect of the silicon-based preceramic polymers, two different polymers were used: poly(methylsilyne) (PMSy) and allylhydridopolycarbosilane (SMP-10) where the latter was a commercially available silicon carbide precursor. Triphenylphosphate (TPP) and a metal complex were also used in polypropylene based composites to gain a synergy with the silicon containing polymers. The polymer composites were prepared using a twin-screw extruder and molded in an injection molding machine. As a result of the flammability tests, it was seen that in order to achieve a significant decrease in the flammability of polypropylene, at least 20 wt% additive was needed. Furthermore, it was observed that the most significant improvement in flame retardancy was obtained in PP/10SMP/5TPP/5M sample containing 10 wt% SMP-10, 5 wt% TPP and 5 wt% metal complex with a limiting oxygen index (LOI) value of 23.5%. This was explained by the synergy obtained by SMP-10, TPP and the metal complex. With the addition of these silicon containing polymers, thermal properties of the composites increased to a great extent. For the mechanical properties, it was seen that impact strength of the composites significantly increased with the addition of SMP-10, PMSy and TPP.

A new polythiophene derivative, poly-2,3-bis(4-tert-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl)quinoxaline PHTQ was synthesized by both chemical and electrochemical polymerization and its electrochemical properties were reported. The monomer was electrochemically polymerized in the presence of tetrabutylammonium hexafluorophosphate(TBAPF6) as the supporting electrolyte in dichloromethane-acetonitrile (5:95, v:v). Nuclear magnetic resonance spectroscopy (1H-NMR, 13C-NMR) was utilized for the characterization of the monomer and the soluble polymer. The polymer was further characterized by Gel Permeation Chromatography (GPC). Spectroelectrochemistry and switching ability of the polymer were investigated by UV&ndash / vis spectrophotometer and cyclic voltammetry. The polymer revealed three distinctive colors upon doping which indicated that the polymer is multichromic. Tert-butyl group on the pendant phenyl rings and hexyl groups on thiophene enhanced the solution processability of the electrochromic polymer. The electrochemical and spectral properties of the chemically synthesized polymer were investigated via spray coating on ITO glass slides. Electrochemical copolymerization of 2,3-bis(4-tert-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl) quinoxaline (HTQ) with 3,4-ethylenedioxythiophene(EDOT) was performed to fulfill a strategy in achieving fine-tuned electrochromic properties. The copolymer, P(HTQ-co-EDOT) was characterized via detailed studies of cyclic voltammetry and spectroelectrochemistry. Band gap (Eg) of the copolymer was calculated as 1.4 eV and showed 34 % optical contrast with switching times less than 1 second.

Thesis (PhD) -- University of Western Sydney, 2002. / "A candidate for the degree of Doctor of Philosophy." "A thesis submitted in the School of Science, Food and Horticulture, University of Western Sydney." "June 2002" Bibliography: leaves 303 - 305.

A new neutral state green polymer, poly (2,3-bis(4-tert-butylphenyl)-5,8-di(1H-pyrrol-2-yl) quinoxaline) (PTBPPQ) was synthesized and its copolymer with bis(3,4-ethylenedioxythiophene) (BiEDOT) and 4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-dodecyl-2H-benzo [1,2,3] triazole (BEBT) were produced. Finally polymers&rsquo / potential use as an electrochromic material was investigated. Electrochromic properties of the polymers were investigated by several methods including spectroelectrochemistry, kinetic and colorimetry studies. Key properties of conjugated polymers such as band gap, maximum absorption wavelength, the intergap states that appear upon doping and evolution of polaron and bipolaron bands were investigated via spectroelectrochemistry experiments. Switching times and optical contrasts of the homopolymer and the copolymer were evaluated via kinetic studies. Copolymer of TBPPQ with BiEDOT and BEBT were electrochemically synthesized and characterized. Resulting copolymer films have distinct electrochromic properties and revealed multichromism through the entire visible region. Although BiEDOT and BEBT have different oxidation potentials, the resulting copolymers have very similar redox behaviors. In a monomer free solution, both copolymers show four colors from purple, gray, light green to transmissive blue with the variation of the applied potential. Copolymerization with BiEDOT and BEBT not only decreases the band gap, Eg, but also enhances the electrochromic and optical properties. Hence, electrochemical copolymerization is considered to be a powerful tool to improve the electrochromic properties of quinoxaline derivatives. It should be noted that PTBPPQ is one of the few examples of neutral state green polymeric materials with superior switching properties. Hence, PTBPPQ can be used as a green polymeric material for display technologies.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology Chemistry in the Faculty of (Science) Supervisor: Professor T.N. van der Walt Bellville campus Date submitted: October 2011 / It is important to quantify polymeric components in a coating because they greatly influence the performance of a coating. The difficulty associated with analysis of polymers by Fourier transform infrared (FTIR) analysis’s is that colinearities arise from similar or overlapping spectral features. A quantitative FTIR method with attenuated total reflectance coupled to multivariate/ chemometric analysis is presented. It allows for simultaneous quantification of 3 polymeric components; a rheology modifier, organic opacifier and styrene acrylic binder, with no prior extraction or separation from the paint. The factor based methods partial least squares (PLS) and principle component regression (PCR) permit colinearities by decomposing the spectral data into smaller matrices with principle scores and loading vectors. For model building spectral information from calibrators and validation samples at different analysis regions were incorporated. PCR and PLS were used to inspect the variation within the sample set. The PLS algorithms were found to predict the polymeric components the best. The concentrations of the polymeric components in a coating were predicted with the calibration model. Three PLS models each with different analysis regions yielded a coefficient of correlation R2 close to 1 for each of the components. The root mean square error of calibration (RMSEC) and root mean square error of prediction (RMSEP) was less than 5%. The best out-put was obtained where spectral features of water was included (Trial 3). The prediction residual values for the three models ranged from 2 to -2 and 10 to -10. The method allows paint samples to be analysed in pure form and opens many opportunities for other coating components to be analysed in the same way.