Person: KAHRAMAN, MEMET VEZİR
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KAHRAMAN
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MEMET VEZİR
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Publication Metadata only Synthesis and characterization of UV-curable dual hybrid oligomers based on epoxy acrylate containing pendant alkoxysilane groups(ELSEVIER SCIENCE SA, 2006) KAHRAMAN, MEMET VEZİR; Bayramoglu, Gulay; Kahraman, M. Vezir; Kayaman-Apohan, Nilhan; Gungor, AtillaThis work involves the synthesis of novel hybrid oligomers based on a UV-curable epoxy acrylate resin (EA). The EA resin was modified with various amount of 3-isocyanatopropyl trimethoxysilane (IPTMS) coupling agent. The modification percentage of the hybrid oligomer was varied from 0 to 50 wt.%. UV-curable, hard and transparent organic-inorganic hybrid coatings were prepared on Plexiglas substrates and their characterization was performed by the analyses of various properties such as hardness, gloss, tape adhesion test and stress-strain test. Results from the mechanical measurements show that the properties of hybrid coatings improve with the increase in modification ratio. The thermal behavior of coatings was also evaluated. It is observed that the thermal stability of epoxy acrylate coatings is enhanced with incorporation of siloxane. Gas chromatography/mass spectrometry analyses showed that the initial weight loss obtained in thermogravimetric analysis is due to the degradation products of the photoinitator and the acrylic acid moiety of acrylic monomers. (c) 2006 Elsevier B.V. All rights reserved.Publication Metadata only Sulfathiazole-based novel UV-cured hydrogel sorbents for mercury removal from aqueous solutions(PERGAMON-ELSEVIER SCIENCE LTD, 2009) KÖK YETİMOĞLU, ECE; Yetimoglu, Ece Koek; Kahraman, Memet Vezir; Bayramoglu, Guelay; Ercan, Oezgen; Apohan, Nilhan KayamanSulfathiazole-based novel hydrogel sorbents P(Sulti/hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc)) were prepared by UV irradiation and used for the removal of mercury(II) ion from aqueous media. Hydrogels have been characterized by SEM and thermogravimetric analysis (TGA) techniques. The influence of the uptake conditions was investigated; maximum Hg(II) ion adsorption capacity obtained was 13.46 +/- 1.15mg g(-1) at pH 5.0. The hydrogels were tested several times without loss of adsorption capacity. The selectivity of the hydrogel towards to Hg(II), Cd(II) and Zn(II) ions tested was Hg>Cd>Zn. (C) 2008 Elsevier Ltd. All rights reserved.Publication Metadata only Preparation and characterization of light curable hybrid coating: Its potential application for dental restorative material(SPRINGER, 2008) KAHRAMAN, MEMET VEZİR; Guengoer, Atilla; Kayaman-Apohan, Nilhan; Mert, Ayse; Kahraman, M. VezirThe objective of this study was to synthesize a dual-functional light curable resin by the reaction between acrylated cycloaliphatic epoxy resin and 3-isocyanatopropyltrimethoxysilane and investigate the performance of this oligomer in the preparation of resin-based composite restoratives. FT-IR and (29)Si-NMR were used to characterize the structure of the hybrids. The char yields of the hybrids increased with inorganic content comes from TEOS (tetraethylorthosilicate) and synthesized SiUA oligomers. Gel content of polymeric films was found to be between 95% and 98%. Swelling was found to be between 3.1% and 3.8%. Weight loss of coated human teeth in synthetic saliva solution was found to be among 1% and 2%. There was a systematic increase in the modulus and tensile strength with the increase of inorganic content. On the other hand, elongation at break did not changed. Prepared hybrid coating materials exhibited improvement in tensile properties and hardness, when photo chemically cured.Publication Metadata only Preparation and Characterization of UV-Curable, Boron-Containing, Transparent Hybrid Coatings(WILEY, 2011) KAHRAMAN, MEMET VEZİR; Mulazim, Yusuf; Kahraman, Memet Vezir; Apohan, Nilhan Kayaman; Kiziltas, Sahip; Gungor, AtillaA series of ultraviolet (UV)-curable, boron-containing hybrid coatings were prepared by an anhydrous sol-gel technique from a mixture of an acrylated bisphenol A based epoxy resin, methacryloxymethyl triethoxysilane, and boric acid. The use of boric acid allowed the hydrolysis and condensation of hybrid silicon alkoxides without the further addition of water or a catalyst. The chemical structure of the boron-containing hybrid coatings was characterized with Fourier transform infrared, real-time infrared, and Si-29 cross-polarization/magic-angle spinning NMR techniques. UV-curable coatings were applied to polycarbonate and Plexiglas substrates. The physical and mechanical properties of the UV-cured coatings (e.g., pendulum hardness, pencil hardness, con-tact angle, gel content, methyl ethyl ketone rubbing test, tensile test, abrasion resistance, chemical resistance, neutron absorption, and limiting oxygen index) were examined. The hybrid coatings showed a significant enhancement in their radiation-shielding properties. The thermal behavior of the coatings was also evaluated. It was observed that the thermal stability of the coatings mainly depended on their boron and silicate contents. The results of all analyses of the free films and coatings were examined. VC 2010 Wiley Periodicals, (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 2112-2121, 2011Publication Metadata only Adsorption of Au(III) ions from aqueous solutions by thiol-ene photoclick hydrogels and its application to electronic waste and geothermal water(ELSEVIER SCIENCE BV, 2014) KÖK YETİMOĞLU, ECE; Firlak, Melike; Yetimoglu, Ece Kok; Kahraman, Memet VezirThis work describes the preparation and characterization of a new thiol-ene hydrogel by photoinitiated polymerization of pentaerythritoltetrakis(3-mercaptopropionate) (Penta3MP4), acrylic acid (AAc) and poly(ethylene glycol) dimethacrylate (PEGDA) as monomers and photo initiator(2,2-dimethoxy-2-phenylacetophenon) for its use as adsorbent. The thiol-ene hydrogel was characterized by using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Real-Time Fourier Transform Infrared Spectroscopy (RT-FTIR), Scanning Electron Microscopy (SEM), Thermal Gravimetric Analyze (TGA) techniques; the swelling behavior and gelation ratio of hydrogel were also investigated. The adsorption capability of the hydrogel against Au(III) ions was investigated. The effects of pH, agitation time, initial metal ion concentration and different metal ions on adsorption capacity were examined. Equilibrium studies have been carried out to determine the capacity of the hydrogel for adsorption of Au(III) ions, Langmuir and Freundlich adsorption models were applied to describe the experimental isotherms and isotherms constants. Equilibrium data were found to fit very well with Langmuir model. The reusability of the hydrogel was also investigated and the preconcentration factor of the hydrogel was determined. The proposed method was applied to Dikili Geothermal Water and computer circuit board scrap. The analytical performance of the method was also determined. (C) 2014 Elsevier Ltd. All rights reserved.Publication Metadata only Preparation and evaluation of linseed oil based alkyd paints(ELSEVIER SCIENCE SA, 2014) OKTAY, BURCU; Iseri-Caglar, Dondu; Basturk, Emre; Oktay, Burcu; Kahraman, M. VezirAlkyd resins are produced with reaction of oil or fatty oil, polyol and polyacid. Alkyd resins are commonly used in coating and paint industry due to ease of application in changing environmental conditions. Linseed oil based paints executed all requirements of technical properties, drying time, storage properties, simplicity in maintenance, appearance, economy, etc. In this study, linseed oil based alkyd resins having different oil contents were synthesized Paint formulations were prepared by mixing alkyd resin and various additives such as huntite, Aerosil R972, talc, titanium dioxide, dryer, wetting agent and anti-skinning agent. All formulations were applied on paper test plates and were dried at 30 degrees C. The obtained coatings were characterized by pencil hardness test, pendulum hardness test, chemical resistance test, cross-cut test, contact angle and gloss measurement. Also thermal and morphological properties were investigated by thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM) respectively. The thermal stability of the paint materials are improved with by increasing the amount of huntite and Aerosil R972 in the paint compositions. (C) 2013 Elsevier B.V. All rights reserved.Publication Metadata only Preparation and characterization of photocured thiol-ene hydrogel: Adsorption of Au(III) ions from aqueous solutions(WILEY, 2012) KÖK YETİMOĞLU, ECE; Firlak, Melike; Kahraman, Memet Vezir; Yetimoglu, Ece KokIn this study, photocured a novel thiol-ene hydrogels based on P(Penta3MP4/PEG-DA/HEMA) were investigated for adsorption of Au(III) ions from aqueous solutions purposes. The photopolymerization kinetics of thiol-ene-based formulations was investigated by real-time infrared spectroscopy. The chemical composition and surface morphology of hydrogels were also characterized. The effect of different parameters on Au(III) adsorption efficiency was examined in detail. Better adsorption behavior was achieved for Au(III) by P(Penta3MP4/PEG-DA/HEMA) F1 hydrogels. The maximum uptake for Au(III) was at pH 0.5. Both Langmuir and Freundlich adsorption isotherm models were applied and the reusability of thiol-ene hydrogels investigated. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012Publication Metadata only Preparation and performance on polycarbonate of B/F/Si-containing hybrid coatings(WILEY-BLACKWELL, 2013) KAHRAMAN, MEMET VEZİR; Zeytuncu, Bihter; Kahraman, Memet Vezir; Yucel, OnuralpA series of UV-curable B/F/Si-containing hybrid coatings was prepared by the anhydrous sol-gel technique. The chemical structure of the coatings was characterized by FTIR, RTIR, and 1HNMR techniques. The UV-curable coatings were applied to polycarbonate substrates. The physical and mechanical properties of the UV-cured coatings, such as pendulum hardness, pencil hardness, contact angle, gel content, MEK rubbing test values, tensile strength, abrasion resistance, and gloss, were examined. Thermal gravimetric analysis (TGA) was done. The relative flammability of the hybrid coatings was tested by the limiting oxygen index (LOI) method. Results of all analyses conducted on the free films and coatings are discussed. J. VINYL ADDIT. TECHNOL., 19:3946, 2013. (c) 2013 Society of Plastics EngineersPublication Metadata only The coating performance of adipic acid modified and methacrylated bisphenol - A based epoxy oligomers(WILEY, 2007) KAHRAMAN, MEMET VEZİR; Bayramoglu, Guelay; Kahraman, M. Vezir; Kayaman-Apohan, Nilhan; Guengoer, AtillaIn the present work adipic acid modified and methacrylated bisphenol A based epoxy resins were prepared. The structures of oligomers were characterized by FT-IR. UV curable clear coatings were applied on aluminum substrates. The physical and mechanical properties of UV-cured coatings such as gel content, solvent resistance, hardness, gloss, flexibility and tensile tests were examined. In addition, the thermal behavior of coatings was also evaluated. It is observed that the tensile properties and thermal stabilities of modified epoxy methacrylate coatings mainly depend on the adipic acid content. The best results were obtained with 5 wt% adipic acid modification. Copyright (C) 2007 John Wiley & Sons, Ltd.Publication Metadata only UV cured thiol-ene flame retardant hybrid coatings(ELSEVIER SCIENCE SA, 2013) OKTAY, BURCU; Basturk, Emre; Oktay, Burcu; Kahraman, Memet Vezir; Apohan, Nilhan KayamanIn this study, bis-(triethoxysilylpropyl) phenyl phosphamide (BESPPA) was synthesized by the reaction between dichlorophenyl phosphine oxide and 3-aminopropyltriethoxysilane. The chemical structure of the BESPPA was characterized with Fourier transform infrared and NMR techniques. Flame retardant, BESPPA and sol gel precursor containing hybrid materials were prepared by thiol-ene polymerization with the aim to improve their final thermal and flame retardant properties. The thermal stabilities of the phosphorous/sol-gel containing UV-cured hybrid materials were investigated by thermogravimetric analysis. The results showed that the addition of sol-gel precursor and BESPPA into the organic network also improves the thermal-oxidative stability of the hybrid materials. The flame-retardant properties of the UV-cured hybrid materials were also studied. Furthermore, the phosphorus silicon synergistic effect on LOI enhancement and increasing flame retardancy of the UV-cured hybrid materials were demonstrated. An LOI enhancement from 20.7 to 26.5 is observed for organic resins containing both phosphorus and silicon. The surface morphology was also characterized by scanning electron microscopy (SEM). SEM studies indicated that inorganic particles were dispersed homogenously throughout the organic matrix. (C) 2012 Elsevier B.V. All rights reserved.