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Öğe Coating, mechanical and thermal properties of epoxy toluene oligomer modified epoxy resin/sepiolite composites(ELSEVIER SCIENCE SA, 2012) Ahmetli, Gulnare; Deveci, Huseyin; Soydal, Ulku; Seker, Asli; Kurbanli, RefikaIn this research, epoxy toluene oligomer (ETO) was synthesised from toluene and epichlorhydrin, which was used as co-matrix in 50 wt.% with commercial epoxy resin (ER). Its chemical structure was characterised with FTIR spectroscopy and chemical analyses. ETO was found as an effective flame retardant for ER. Modification of ER with ETO in 50 wt.% increased percentage elongation at break of neat ER about 67 times. The rigid filler used in epoxy polymer matrix was the modified and unmodified sepiolite. The appropriate sepiolite amount in all cases was determined to be 5 wt.%. Scanning electron microscopy (SEM) was used for characterisation of surface and cross sections of the composites to verify the results. Modification of sepiolite increases the T-5, T-10, and T-50 of neat ETO-ER by 10, 7, and 5 degrees C, respectively. Surface hardness and tensile strength of all composites were higher than those of neat ETO-ER polymer matrix. ETO-ER/modified sepiolite coating showed the best adhesion results and exhibited perfect resistance to 3% NaCl and 10% NaOH solutions. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.Öğe DETERMINING THE ELASTIC PROPERTIES OF EPOXY/SEMICONDUCTIVE GLASS COMPOSITES BY ULTRASONIC METHOD(AMER INST PHYSICS, 2014) Oral, Imran; Soydal, UlkuThe purpose of this study is to investigate the effects of the type and amount of semiconductive fillers on the elastic properties of epoxy (ER) / semiconductive glass (SG) composites by ultrasonic velocity measurments. Different semiconducting glasses (SG) binary systems such as As2S3-TlS and As2Se3-TlS were synthesized. ER/SG composites were formed 15 wt. % of fillers and characterized by ultrasonic velocity measurments. The ultrasonic wave velocities of composites were measured with the pulse-echo method at room temperature by a flaw detector. The values of the acoustic impedance, Poisson's ratio, and elasticity constants of the samples were calculated by the measured values of both longitudinal and shear ultrasonic wave velocities. According to the results, The highest elastic properties values were found in the ER/SG-3 composite using 50% As2Se3-50% TlS.Öğe Effect of Modification with Various Epoxide Compounds on Mechanical, Thermal, and Coating Properties of Epoxy Resin(HINDAWI LTD, 2016) Cerit, Alaaddin; Marti, Mustafa Esen; Soydal, Ulku; Kocaman, Suheyla; Ahmetli, GulnareEpoxy resin (ER) was modified with four different epoxide compounds, 4,5-epoxy-4-methyl-pentane-2-on (EMP), 3-phenyl-1,2-epoxypropane (PhEP), 1-chloro-2,3-epoxy-5-(chloromethyl)-5-hexene (CEH), and a fatty acid glycidyl ester (FAGE), to improve its chemical and physical properties. The effects of the addition and amount of these modifiers on mechanical, thermal, and coating properties were investigated. Atomic force microscopy was used to observe the changes obtained with the modification. The influence of the modifying agents on the curing process was monitored through FTIR spectroscopy. The curing degrees of ER and modified ERs (M-ERs) were found to be over 91%. The results showed that tensile strength of ER improved till 30% (wt.) with addition of the modifier content. Modification with EMP and PhEP remarkably enhanced the thermal stability of ER to be highly resistant to the corrosive media.Öğe Epoxy resin/polymer blends: Improvement of thermal and mechanical properties(WILEY-BLACKWELL, 2012) Ahmetli, Gulnare; Deveci, Huseyin; Soydal, Ulku; Gurler, Sevgi Pistil; Altun, AhmetFatty acid waste was recycled as raw material and utilized to synthesize epoxy (HP) or unsaturated ester group (OEE) containing polymers. The radicalic polymerization between the styrene and itaconic acid was carried out, too. Glycidyl ester of styrene-itaconic acid copolymer was obtained by esterification reaction with epichlorohydrin. The polymers were characterized by means of Fourier transform infrared spectroscopy and chemical analysis. The polymers were incorporated into diglycidyl ether of bisphenol A type commercial epoxy resin to prepare composites. The effects of polymer structure and amount on the physico-mechanical and thermal properties of epoxy were investigated. Surface hardness, tensile strength, percentage elongation and stress at maximum load of the composites were obtained higher than pure epoxy resin. The composites reinforced with bio-based polymers showed about 74.55243% increase in elastic modulus over the pure epoxy matrix. Obtained Young's modulus values were higher for composites with styrene-based polymers. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012Öğe Evaluation of sugar mill lime waste in biobased epoxy composites(WILEY, 2018) Soydal, Ulku; Marti, Mustafa Esen; Kocaman, Suheyla; Ahmetli, GulnareIn this study, precipitated calcium carbonate-lime waste (LW) from sugar beet production was recycled as a raw material for the preparation of composite materials. Epoxidized soybean oil (ESO) was used as a co-matrix in 50 wt% with bisphenol A-type epoxy resin (ER). The composites were prepared with LW in varied per cent values (10-50 wt%) using the casting technique. The morphology of the composites was characterized by X-ray diffraction and scanning electron microscopy. Effects of ESO and LW amounts on the mechanical and thermal properties of the composites were investigated. Modification with ESO remarkably enhanced the plasticity of the material, but decreased the curing degree about 2%. The modified ER shows about 13% increase in elongation at break over the pure epoxy matrix. Density and hardness of neat epoxy matrices were observed to increase with the LW content in the composite. Tensile strengths of all composites are higher than that obtained with neat epoxy. The thermogravimetric analyses show that ESO and LW significantly improve the thermal stability of neat ER at the temperatures above 300 degrees C. The best thermal results were obtained with the composites containing 40- and 50 wt% LW. The residual weights of the composites are higher than that of neat ER and ER-ESO, and increases with the increasing LW amount. The T-5,T- T-10 and T-50 data of the composites are higher than those of neat ER and ER-ESO. The water sorption values of the ER-ESO matrix composites are in the range of 1.0-2.9 wt%. POLYM. COMPOS., 39:924-935, 2018. (c) 2016 Society of Plastics EngineersÖğe The Influence of Semiconductive Binary Sb2S3-Yb3S4 System on Electrical Conductivity Property of Epoxy Composites(AMER INST PHYSICS, 2014) Soydal, Ulku; Ahmetli, Gulnare; Kocaman, SuheylaThe purpose of this study is to develop the semiconductive composites. Semiconducting glass (SG) binary system Sb2S3-Yb3S4 in mole ratio 1:1 was synthesized and was doped with I-2. Next, electrically conductive DGEBA-type epoxy resin (ER)/SG-filled composites and epoxy toluene oligomer (ETO) modified epoxy resin-SG filled composites were developed with 3-10 wt. % of fillers and characterized. As a result, the effects of the modifier and amount of semiconductive filler on the electrical properties of commercial epoxy resin were examined. Percolation concentration was 7 wt. % for all composites. For the SG-reinforced composites, the dispersion of the fillers is investigated by X-ray diffraction (XRD) and by scanning electron microscopy (SEM).Öğe The influence of semiconductive binary systems on electrical conductivity, mechanical, and thermal properties of epoxy composites(WILEY, 2018) Soydal, Ulku; Ahmetli, GulnareThe purpose of this study is to develop epoxy composites with improved mechanical, thermal, and electrical properties. Semiconducting glass (SG) binary systems such as As2S3-TlS and As2Se3-TlS were synthesized in various mole ratios (1:1 and 1:3). Electrically conductive DGEBA-type epoxy-SG-filled composites were developed containing 1-15 wt% of fillers and characterized by X-ray diffraction and scanning electron microscopy techniques. As a result, the effects of the type and amount of semiconductive filler on the mechanical, thermal, and electrical properties of commercial epoxy resins (ERs) were examined. It was found that I-2 doping of the filler significantly increased the electrical conductivity of the composites up to 10(-3) S cm(-1). Percolation concentrations were found to be 7 wt% for all composites studied. The maximum tensile strength changed in the range of 86-114 MPa was obtained with 5-10 wt% of SG particles. In addition, the thermal behavior and stability of the epoxy composites were studied using thermogravimetric analysis. The incorporation of SG particles increased the 10% decomposition temperature of neat epoxy by 5 degrees C-35 degrees C. ER/SG coatings showed the best adhesion results and perfect resistance to 3% NaCl, 3% HCl, and 5% NaOH solutions. POLYM. COMPOS., 39:681-690, 2018. (c) 2016 Society of Plastics EngineersÖğe Modification of the epoxy resin with epoxide and ester group containing oligomers and compounds(ESTONIAN ACADEMY PUBLISHERS, 2015) Ahmetli, Gulnare; Yazicigil, Zafer; Soydal, UlkuEpoxy toluene oligomers (ETO) are very important substances due to effective functional groups in their structure and they are especially used as polymer additives that have been synthesized from toluene and epichlorhydrin. Flame-retardant properties of the neat epoxy resin (ER), ETO, and ETO/ER blend thermoset were evaluated by UL94 vertical flammability test. The chlorine atoms in ETO increase the stability of the polymer material against burning. For the synthesis other polymers, first the waste product of the industrial vegetable oil refinement acid oil was transformed into the glycidyl ester (FAGE). Unsaturated oligo(ether-ester) (OEE) was prepared by ring-opening polymerization of the propylene oxide (PO) with FAGE in the presence of cationic catalyst BF3 center dot O(C2H5)(2). Its chemical structure was characterized with FTIR spectroscopy. These polymers, isoamyl methacrylate (AMA) and 1,2-epoxy-hexane-5-en (EH) were used as modifiers in the DGEBA-type epoxy resin. The effects of the modifier structure and amount on the mechanical properties of epoxy were investigated. Tensile strength and Young's modulus of the modified samples were found higher than those of the neat epoxy resin.Öğe Study on the reuse of marble and andesite wastes in epoxy-based composites(WILEY, 2018) Soydal, Ulku; Kocaman, Suheyla; Marti, Mustafa Esen; Ahmetli, GulnareAndesite- (AW) and marble-dust wastes (MW) were recycled to be used in composite preparation. Both were obtained from local industrial sources. Commercially available epoxy resin (ER) and its modified version with polyaniline (PANI) were used as the neat polymer matrix. The dispersion of the fillers was investigated by X-ray diffraction and scanning electron microscopy. The effects of PANI and waste loading on the mechanical, thermal, electrical, water sorption, and corrosion properties were investigated. The optimum loading levels for MW or AW in the composites were found to be 20 wt%. Using thermogravimetric analyses, thermal behavior and stability of the composites prepared were probed. The incorporation of PANI and waste fillers increased the T-10 temperature by 10-33 degrees C and the tensile strength by 4-51 MPa of neat ER. The composites containing 10-30 wt% AW filler were found to be semiconductive and electrical conductivity decreased with the increase in AW content. The PANI-ER/AW composite showed perfect resistance to corrosion and also exhibited the best adhesion. POLYM. COMPOS., 39:3081-3091, 2018. (c) 2017 Society of Plastics EngineersÖğe Synthesis and study of the oligo(ether-ester)s based on butylene oxide(JOHN WILEY & SONS INC, 2008) Ahmetli, Gulnare; Kocak, Ahmet; Soydal, UlkuUnsaturated oligo(ether-ester) was prepared by ring-opening polymerization of butylene oxide (BO) with glycidyl methacrylate (GMA) in the presence of cationic catalyst (BF3O)-O-center dot(C2H5)(2). The effects of mol ratio of the initial components, amount of catalyst, temperature, and reaction times on the copolymerization reaction were examined. Oligo(ether-ester) were achieved in highest yield of 82% after reaction times of 4 h at 0 degrees C. Synthesized copolymer was characterized using spectroscopic (H-1 NMR and IR) and chemical analysis methods. The thermal degradation and softing points of oligo(ether-ester)-styrene composites were studied. It is shown that crosslinking of the unsaturated oligo(ether-ester) with styrene takes place through the use of thermostable materials. (C) 2008 Wiley Periodicals, Inc.Öğe Ultrasonic characterization of andesite waste-reinforced composites(SPRINGER, 2017) Oral, Imran; Soydal, Ulku; Bentahar, MouradThe epoxy resin used in this study is modified with 5 wt% of polyaniline. Then electrically conductive modified epoxy resin (MER) (as matrix) and different weight amounts (10-30 wt%) of andesite waste (AW) as filler are mixed together to obtain the andesite waste-reinforced epoxy resin composites. The effects of filler amount on the electrical and ultrasonic properties of the modified epoxy resin are examined. The effects of AW amount on the ultrasonic properties of the obtained MER/AW composites are investigated by ultrasonic pulse-echo method. The conductivity of the composites is measured by a four-point probe (FPP) method, and the morphologies of the samples are investigated by scanning electron microscopy (SEM). Experimental results show that increasing the amount of AW causes a linear increase in the elastic properties. On the other hand, the same amounts of AW decrease the electrical conductivity of MER.
