The synthesis of ion-exchange resin which can be used in various separation and chemical purposes, such as diffusion dialysis, electro dialysis, electrolysis and fuel cells has of considerable interest. For all these applications, the interactions of the ionic groups and the resulted morphologies are critical for establishing the unique properties. Considerable researches have been continued to understand the microstructure of these materials. The aim of this study is to synthesize polypropylene (PP) based ion exchange resins and to investigate their ion-exchange properties. In the first part of this study polypropylene was functionalized by grafting maleic anhydride onto the polypropylene and the product was characterized by ATR. The effect of maleic anhydride introduced to the grafting medium and the effect of the radical initiator on the maleic anhydride content of the MA-g-PP samples were investigated. In the second part, neutralization of the MA-g-PP samples with Na+, K+, Mg2+ and Ca2+ ions and peroxide cross-linking of neutralized MA-g-PP samples were performed. Characterization of the neutralized MA-g-PP samples were performed by ATR and SEM-EDX. In the last part of the study, ion exchange properties of MA-g-PP resins towards Cu2+, Co2+, Cd2+, Pb2+ and Fe3+ ions at different pHs were investigated by batch equilibrium method. Rate of metal uptake, concentration effect on the metal uptake and regeneration of the MA-g-PP samples were also examined.

This thesis is aimed to understand the role of nanofiller type, nanofiller dispersion, nanofiller geometry, and, presence of reinforcing fibers in flame retardancy of polymer nanocomposites. For this purpose, montmorillonite nanoclays, multi-walled carbon nanotubes, halloysite clay nanotubes and silica nanoparticles were used as nanofillers in polymeric matrices of poly (methyl methacrylate) (PMMA), high-impact polystyrene (HIPS), polylactide (PLA) and polyamide-6 (PA6) containing certain conventional flame retardant additives. Furthermore, the influence of nanofiller and flame retardant additives on fiber/matrix interfacial interactions was studied. Materials were prepared by twin-screw extrusion melt-mixing and ultrasound-assisted solution-mixing techniques. Characterization of nanocomposite morphology was done by X-ray diffraction and transmission electron microscopy. Flame retardancy was investigated by mass loss cone calorimetry, limiting oxygen index measurements and UL94 standard tests. Flame retardancy mechanisms were revealed by characterization of solid fire residues by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy and X-ray diffraction. Thermal degradation and stability was studied using thermogravimetric analysis. Mechanical properties were determined by tension tests and fracture surfaces were observed under scanning electron microscope. Influence of nanofiller type was investigated comparing the behavior of montmorillonite nanoclay and multi-walled carbon nanotube reinforced PMMA nanocomposites containing phosphorous/nitrogenous intumescent flame retardant. Carbon nanotubes hindered the formation of intumescent inorganic phosphate barrier which caused the samples to be exposed to larger effective heat fluxes during combustion. Contrarily, nanoclays physically reinforced the protective barrier without disrupting the intumescent character, thereby allowing for lower heat release and mass loss rates, and increased amounts of residue upon combustion. Influence of nanofiller dispersion was studied comparing nanocomposite and microcomposite morphologies in montmorillonite nanoclay reinforced HIPS containing aluminum hydroxide flame retardant. Relative to microcomposite morphology, reductions in peak heat release rates were doubled along with higher limiting oxygen index and lower burning rates with nanocomposite formation. Improved flame retardancy was attributed to increased amounts of char residue and lower mass loss rates. Nanocomposite formation allowed for the recovery of tensile strength reductions caused by high loading level of the conventional flame retardant additive in polymer matrix. Influence of nanofiller geometry was investigated for phosphorus based intumescent flame-retarded PLA nanocomposites. Fire performance was increased in the order of rod-like (1-D) &lt / spherical (0-D) &lt / &lt / plate-like (2-D) geometries which matched qualitatively with the effective surface area of nanoparticles in the nanocomposite. Well-dispersed plate-like nanoparticles rapidly migrated and accumulated on exposed sample surface resulting in the formation of strong aluminum phosphate/montmorillonite nanocomposite residue. Mechanical properties were increased in the order of 0-D &lt / 1-D &lt / 2-D nanofillers corresponding to the order of their effective aspect ratios in the nanocomposite. Influence of fiber reinforcement was studied for montmorillonite nanoclay containing short-glass fiber-reinforced, phosphorus/nitrogen based flame-retarded PA6 composites. Substitution of a certain fraction of conventional additive with nanofiller significantly reduced peak heat release rate, delayed ignition and improved limiting oxygen index along with maintained UL94 ratings. Improved flame retardancy was ascribed to the formation of a nanostructured carbonaceous boron/aluminum phosphate barrier reinforced by well-dispersed montmorillonite nanolayers. Fiber/matrix interfacial interactions in flame-retarded PA6 and HIPS containing nanoclays were investigated using a micromechanical approach, and it was found that the influence of nanoclay on the interface depends on crystallinity of polymer matrix. While the fiber/matrix interfacial strength is reduced with nanoclay incorporation into amorphous matrix composites, significant interfacial strengthening was imparted by large surface area, well-dispersed clay nanolayers acting as heterogeneous nucleation sites for the semi-crystalline matrix.

Three new azobenzene containing conjugated monomers were designed and synthesized. Resulting monomers were characterized by means of 1H NMR and 13C NMR techniques. Monomers (E)-1,2-bis(4-(thiophen-2-yl)phenyl)diazene (M1), (E)-1,2-bis(4-(4-hexylthiophen-2-yl) phenyl) diazene (M2) and (E)-1,2-bis(2-fluoro-4-(4-hexylthiophen-2-yl)phenyl) diazene (M3) were electrochemically polymerized using cyclic voltammetry to give polymers P1, P2 and P3. The polymers were subjected to spectroelectrochemical and kinetic studies in order to obtain information about their elecrochromic characteristics. P1 and P2 were pale-yellow in their neutral states and blue in oxidized states while P3 showed multichromic property due to having polaron bands in visible region of the spectrum. Addition of fluorine atoms to the backbone of P3, lowered the LUMO level of P3 thus gained the polymer n-doping property. In the second part of this thesis poly((9,9-dioctylfluorene)-2,7-diyl-(4,7-bis(thien-2-yl) 2-dodecyl-benzo[1,2,3]triazole)) (PFTBT) polymer was mixed with common electron acceptor Phenyl-C61-butyric acid methyl ester (PCBM) and used in organic solar cell applications. Active layers containing PFTBT and PCBM were spin casted on ITO coated substrates at varying rotational speeds to obtain active layer thicknesses having different values. Thickness of the active layer was optimized so was the efficiency of organic solar cells. As a result of this optimization study, efficiency of PFTBT containing organic solar cells were increased to 1.06% which is a higher value than previosly reported literature results.

Polyethylene (PE) is one of the most popular polymers used in daily life. However, saturated hydrocarbons cannot absorb the energy of light reaching to earth, so degradation process is rather slow which in return cause disposal problems. On the other hand, it was observed that in presence of oxygen and impurities in the polymer matrix, degradation can be rendered to shorter time intervals. This study covers investigation of effect of three different additives in UV induced oxidative degradation of polyethylene. In this work vanadium (III) acetylacetonate, serpentine and Cloisite 30B were used as additives both together and alone to follow photodegradation of polyethylene. Amount of vanadium (III) acetylacetonate was kept constant at 0.2 wt%, while serpentine and Cloisite 30B were used between 1 and 4 wt%. All compositions were prepared by using Brabender Torque Rheometer, and shaped as thin films by compression molding. Samples were irradiated by UV light up to 500 hours. Mechanical and spectroscopic measurements were carried out in certain time intervals to monitor the degradation. It can be concluded that all combinations of three additives showed the fastest degradation behavior compared to pure PE. In the absence of vanadium (III) acetylacetonate the degradation was slowed and fluctuations were observed in the residual percentage strain at break values. There was not a significant change in tensile strength of all samples. Carbonyl index values followed by FTIR were always in increasing manner. Thermal properties were also investigated by DSC Thermograms and they did not change significantly.

Synthesis of 2-[(3-thienylcarbonyl)oxy]ethyl 3-thiophene carboxylate (TOET), 2,3-bis-[(3-thienylcarbonyl)oxy]propyl 3-thiophene carboxylate (TOPT), and 3-[(3-thienylcarbonyl)oxy]-2,2-bis{[(3-thienylcarbonyl)oxy]}propyl 3- thiophene carboxylate (TOTPT), and their copolymerization either with thiophene or pyrrole were achieved. The chemical structures of the monomers were investigated by Nuclear Magnetic Resonance Spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Electrochemical behavior of the monomers and copolymers were studied by cyclic voltammetry (CV). The resultant conducting copolymers were characterized via FTIR, Thermal Gravimetry Analysis (TGA), Differential Scanning Calorimetry (DSC), and morphologies of the films were inspected by Scanning Electron Microscope (SEM). Conductivities of the samples were measured by using four-probe technique. The electrochromic and spectroelectrochemical properties of the copolymers were investigated.

Synthesis and characterization of conducting copolymers were achieved by using thiophene-3-yl acetic acid cholesteryl ester (CM) and poly (3-methylthienyl methacrylate) (PMTM). A new polythiophene containing a cholesteryl side chain in the &amp / #946 / -position was chemically polymerized in nitromethane/carbon tetrachloride using FeCl3 as the oxidizing agent. Polymerization was also achieved by constant current electrolysis in dichloromethane. Subsequently, conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester (CM), PCM1 (obtained from chemical polymerization method), PCM4 (obtained from constant current electrolysis) with pyrrole were synthesized. Thiophene functionalized methacrylate monomer (MTM) was synthesized via esterification of the 3-thiophene methanol with methacryloyl chloride. The methacrylate monomer was polymerized by free radical polymerization in the presence of azobis (isobutyronitrile) (AIBN) as the initiator. Graft copolymers of poly (3-methylthienyl methacrylate)/polypyrrole, (PMTM2/PPy) and poly (3-methylthienyl methacrylate)/polythiophene, (PMTM2/PTh) were synthesized by constant potential electrolyses. PMTM2 coated Pt electrodes were utilized as the anode in the polymerization of pyrrole and thiophene. Moreover, oxidative polymerization of PMTM1 was studied by galvanostatic and chemical techniques. Characterizations of the samples were performed by CV, FTIR, NMR, DSC, TGA and SEM analyses. Electrical conductivities were measured by the four-probe technique. Immobilization of invertase in conducting copolymer matrices, poly (3-methylthienyl methacrylate) with pyrrole and thiophene was achieved by constant potential electrolysis using the sodium dodecyl sulfate as the supporting electrolyte. Polythiophene was also used for immobilization matrices. Cholesterol oxidase has been immobilized in conducting copolymer of thiophene-3-yl acetic acid cholesteryl ester with polypyrrole (CM/PPy) and polypyrrole (PPy) by the electropolymerization method. p-Toluene sulfonic acid was used as a supporting electrolyte. Kinetic parameters (Kinetic parameters / Vmax and Michaelis-Menten constant / Km) and operational stability of enzyme electrodes were investigated. Surface morphology of the films was also examined.

A new thiophene derivative containing menthyl group (MM) was synthesized and polymerized via chemical and electrochemical methods. Polymers obtained and MM itself were used to synthesize copolymers with pyrrole under conditions of constant potential electrolysis. Cyclic Voltammetry, thermal analysis and scanning electron microscopy analyses were performed for the characterization of samples. Immobilization of invertase and polyphenol oxidase enzymes was performed in the matrices obtained via copolymerization of MM with pyrrole. Immobilization was carried out via entrapment of enzyme in matrices during the polymerization of pyrrole. Temperature optimization, operational stability and shelf-life of the enzyme electrodes were investigated. Maximum reaction rate (Vmax) and Michaelis-Menten constant (Km) were determined. It is known that wine includes phenolic groups that give astringency in high concentrations. Polyphenol oxidase (PPO) converts mono and diphenols to quinone. By analyzing the product, one can find out the amount of phenolic groups. By using obtained enzyme electrodes via immobilization of PPO, amount of phenolics in different wines were analyzed.

In this study, the effects of chain extension and branching on the properties of nanocomposites produced from recycled poly(ethylene terephthalate) and organically modified clay were investigated. As the chain extension/branching agent, maleic anhydride (MA) and pyromellitic dianhydride (PMDA) were used. The nanocomposites were prepared by twin-screw extrusion, followed by injection molding. Recycled poly(ethylene terephthalate), was mixed with 2, 3 and 4 weight % of organically modified montmorillonite. During the second extrusion step, 0.5, 0.75 or 1 weight % of MA or PMDA was added to the products of the first extrusion. As the second extrusion step is reactive extrusion, the anhydrides were added at three different screw speeds of 75, 150, 350 rpm, in order to observe the change of properties with the screw speed. XRD analysis showed that, the interlayer spacing of Cloisite 25A expanded from 19.21 &amp / #506 / to about 28-34 &amp / #506 / after processing with polymer indicating an intercalated structure. PMDA, MA and organoclay content as well as the screw speed did not have a recognizable effect on interlayer distance. In the first extrusion step, nanocomposites containing 3% organoclay content gave significant increase in Young&rsquo / s modulus and decrease in elongation to break values indicating good interfacial adhesion. After the addition of chain extenders, it was observed that both MA and PMDA gave rise to improved mechanical properties of the nanocomposite owing to the branching and chain extending effects that increase the molecular weight. However, PMDA gave better mechanical properties at lower content which makes it a more effective chain extender. DSC analysis showed that MA was more effective in increasing the glass transition temperature and melting temperature in comparison to PMDA.

In this work, methylmethacrylate, MMA was polymerized by ATRP method to obtain low molecular weight living polymers. The initiator was p-toluenesulfonylchloride and catalyst ligand complex system were CuCl-4,4&rsquo / dimethyl 2,2&rsquo / bipyridine. Polymers with controlled molecular weight were obtained. The polymer chains were shown by NMR investigation to be mostly syndiotactic. The molecular weight and molecular weight distribution of some polymer samples were measured by GPC method. The K and a constants in [h]=K Ma equation were measured as 9.13x10-5 and 0.74, respectively. FT-IR and X-Ray results showed regularity in polymer chains. The molecular weight-Tg relations were verified from results of molecular weight-DSC results.

In the first part of this work, the structural and thermal characteristics of polyacrylonitrile, polyacrylonitrile films treated under the electrolysis conditions in the absence of thiophene, polythiophene and the mechanical mixture and a conducting copolymer of polyacrylonitrile/polythiophene have been studied by pyrolysis mass spectrometry technique. The thermal degradation of polyacrylonitrile occurs in three steps / evolution of HCN, monomer, low molecular weight oligomers due to random chain cleavages are followed by cyclization and dehydrogenation reactions yielding crosslinked and unsaturated segments. Pyrolysis of the treated polyacrylonitrile films indicated decrease in the yields of monomer and oligomers, and increase in the amount of products stabilized by cyclization reactions were detected. Polythiophene degrades in two steps / the loss of the dopant and degradation of polymer backbone. The evolution profiles of polythiophene based products from polythiophene/polyacrylonitrile showed nearly identical trends with those recorded during the pyrolysis of pure polythiophene. However, evolution of HCN and the degradation products due to the homolytic cleavages of the polymer backbone continued through out the pyrolysis indicating a significant increase in their production. Furthermore, the yield of thermal degradation products associated with decomposition of the unsaturated cyclic imine segments decreased. A careful analysis of the data pointed out presence of mixed dimers confirming copolymer formation. In the second part of this work, a poly(acrylonitrile-co-butadiene) sample involving monomer units having quite similar molecular weights have been analyzed to investigate the limits of the pyrolysis mass spectrometry technique. Pyrolysis of aged poly(acrylonitrile-co-butadiene) indicated oxidative degradation of the sample. Keywords: conducting copolymer, polyacrylonitrile, polythiophene, polybutadiene, direct pyrolysis mass spectrometry