Person: ÇAKIR, MUSTAFA
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ÇAKIR
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MUSTAFA
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Publication Open Access Effect of Surface Modification of Fumed-Silica on Mechanical Properties of Unsaturated Polyester Composites(2015) ÇELİK, ALİ ALPARSLAN; Çakir, Mustafa; Simsek, Ramazan; Çelik, Ali AlparslanPublication Open Access Çift Kür Olabilen Hidrofob Kaplamaların Mekanik, Yüzey ve Termal Özelliklerinin İncelenmesi(2018-09-30) ÇAKIR, MUSTAFA; Mustafa ÇAKIRÖnemli kaplama teknolojilerinden biri olan ultraviyole (UV) ışıkla sertleştirme yöntemi, artan uygulama alanları ve diğer yöntemlere kıyasla var olan avantajları ile birlikte her geçen gün daha fazla tercih edilmektedir. Bu makalede, bir izosiyanat akrilat olan ICA (Laromer® LR 9000) reçinesi ile monoetilen glikol (MEG), dietilen glikol (DEG) ve hidroksil ile sonlandırılmış perfloropolieter türevi olan floro alkol (Fluorolink® E10-H) içeren reçine sistemleri kullanılarak kaplamalar hazırlanmıştır. Bu reçine sistemlerinin ısı ve UV ile sertleştirilmesi sonucunda farklı oranlarda flor içeren serbest filmler elde edilmiş ve ayrıca alüminyum levhalar üzerine de bu formülasyonlar kaplama yapılmıştır. Elde edilen serbest filmlerin; çekme testi, termogravimetrik analiz (TGA) ve diferansiyel taramalı kalorimetre (DSC) yardımıyla mekanik ve termal özellikleri belirlenmiştir. Ayrıca alüminyum levha üzerine yapılan kaplamaların özellikleri ise; kalem sertlik testi, çapraz kesme testi, parlaklık testi ve temas açısı testi ile gözlemlenmiştir. Sonuçlar incelendiğinde hidrofobik ve parlak bir kaplama elde edildiği görülmüştür. Ayrıca farklı oranlarda eklenen floro alkolün monoetilen glikol içeren yapı ile dietilen glikol içeren yapının mekanik özelliklerinde farklı etkiler yarattığı tespit edilmiştir.Publication Metadata only Magnetic and microwave absorption properties of PVB/Fe3O4 and PVB/NiFe2O4 composites(WILEY, 2018) AKIN, EMRE; Akinay, Yuksel; Hayat, Fatih; Cakir, Mustafa; Akin, EmreElectromagnetic and microwave absorbing properties of Polyvinylbutyral (PVB)/Fe3O4 and PVB/NiFe2O4 composites were investigated in the 1-14 GHz. PVB/filler particles (Fe3O4 and NiFe2O4) composites were prepared with 90/10 mixture ratios via Ultrasonic Probe Sonicator method in solution. The complex permittivity (epsilon-j epsilon) and permeability (- j) of the composites have been measured at different microwave frequencies in 1-14 GHz employing vector network analyzer (Keysight N9926A). The reflection loss (R-L) of composites was calculated and evaluated using theory of the absorbing wall. It was found that, both composites exhibit the large reflection loss and broadband within the frequency range from 1 to 14 GHz for 3, 5, and 7 mm. However, the R-L results show that, when the thickness is 7 mm, the minimum R-L was found to be -22.9 dB (99% power absorption) at the frequency of 13.93 GHz. The Fe3O4/PVB and NiFe2O4/PVB composites have potential application for microwave and radar absorptions. POLYM. COMPOS., 39:3418-3423, 2018. (c) 2017 Society of Plastics EngineersPublication Metadata only Thermal and surface properties of a novel hybrid polyimide containing fluorine chains(2016-11-25) ÇAKIR, MUSTAFA; AKIN E., ÇAKIR M., AKINAY Y.Publication Open Access Properties of UV-Curable Bisphenol-A Glycerolate Diacrylate Coatings_x000D_ Containing 1H,1H,2H,2H-Perfluorodecyl Acrylate Monomer(2018-09-30) AKIN, EMRE; Mustafa Sefa ÇAKIR;Süleyman Emre AKIN;Perihan ULAKAbstract: In this study, fluorine chains were bonded with covalently in epoxy acrylate system via UV light.For this purpose, five different coating samples prepared. Bisphenol-A glycerolate diacrylate (epoxy acrylate)and 1,6-Hexanediol diacrylate were used as the main coating solution. The weight ratio of Bisphenol-Aglycerolate diacrylate and HDDA was determined as 7/3. As a long fluorine chain, 1H,1H,2H,2Hperfluorodecyl acrylate (PFOA) was added into the main coating solution in the ratios of 0.25 wt %, 0.50 wt%, 0.75 wt % and 1 wt %. All prepared solutions were coated on aluminum plates by 75 µm by wire woundapplicator and then cured via UV dryer. Physical properties of coatings were measured by tests such as MEKrubbing test for solvent resistance, gloss 60otest for brightness, cross-cut test for adhesion property and pencilhardness test for scratch resistance. Hydrophobicity was measured as static water contact angle test. The totalsurface energy was calculated by contact angle measurement software. In terms of mechanical properties,sheen impact test (for coating samples) and Shore - D hardness tests (for free film samples) were carried out.By examining the results of all these tests; cross-cut adhesion and gloss 60ovalues decrease with the fluorinecontent. On the other hand, by the increasing within the content of the fluorine chains, Taber abrasionresistance and hydrophobicity increase significantly but sheen impact resistance and Shore - D hardnessvalues decrease slightly. In terms of cost and overall results, the most proper and multifunctional coatingseemed at 0.25 wt %.Publication Open Access E-Cam Elyaf Takviyeli Epoksi Matrisli Kompozit Malzemelerin Elyaf_x000D_ Oranındaki Artış İle Mekanik Özelliklerindeki Değişimlerin İncelenmesi(2018-09-30) ÇAKIR, MUSTAFA; Mustafa Sefa ÇAKIR;Boran BERBEROĞLUÖz: Cam elyaf takviyeli polimer matrisli kompozit malzemeler endüstride, otomotiv sanayinde, inşaat ve diğerbirçok alanda kullanılmakta olan mühendislik malzemeleridir. Bu malzemeler matris yapısını oluşturan birpolimer reçinesi içerisine cam elyafların eklenmesi sonucunda elde edilmektedir. Bu çalışmada vakum desteklireçine transfer metodu ile üretilen ve değişik elyaf oranlarına sahip (hacimce %30, %40, %50 ve %60) kompozitmalzemeler hazırlanmış ve bu malzemelerin mekanik özellikleri incelenmiştir. Bu kompozitlerin üretimindematris malzemesi olarak Epikote 828 epoksi reçinesi kullanılmıştır. Elde edilen plaka halindeki kompozitmalzemelerden ASTM standartlarına uygun olarak numuneler kesilerek çekme, darbe ve üç nokta eğmedeneyleri gerçekleştirilmiştir. Tüm bu çalışmaların sonucunda cam elyaf oranının artmasıyla birlikte kompozitmalzemenin maksimum gerilme, çekme uzama, elastik modülü ve darbe dayanımı özelliklerinin yükseldiğigözlemlenmiştir.Publication Open Access Investigation of Coating Performance of UV-Curable Hybrid Polymers Containing 1H,1H,2H,2H-Perfluorooctyltriethoxysilane Coated on Aluminum Substrates(MDPI AG, 2017-03-02) ÇAKIR, MUSTAFA; Cakir, MustafaThis study describes preparation and characterization of fluorine-containing organic-inorganic hybrid coatings. The organic part consists of bisphenol-A glycerolate (1 glycerol/phenol) diacrylate resin and 1,6-hexanediol diacrylate reactive diluent. The inorganically rich part comprises trimethoxysilane-terminated urethane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, 3-(trimethoxysilyl) propyl methacrylate and sol-gel precursors that are products of hydrolysis and condensation reactions. Bisphenol-A glycerolate (1 glycerol/phenol) diacrylate resin was added to the inorganic part in predetermined amounts. The resultant mixture was utilized in the preparation of free films as well as coatings on aluminum substrates. Thermal and mechanical tests such as DSC, thermo-gravimetric analysis (TGA), and tensile and shore D hardness tests were performed on free films. Water contact angle, gloss, Taber abrasion test, cross-cut and tubular impact tests were conducted on the coated samples. SEM examination and EDS analysis was performed on the fractured surfaces of free films. The hybrid coatings on the aluminum sheets gave rise to properties such as moderately glossed surface; low wear rate and hydrophobicity. Tensile strength of free films increased with up to 10% inorganic content in the hybrid structure and this increase was approximately three times that of the control sample. As expected; the % strain value decreased by 17.3 with the increase in inorganic content and elastic modulus values increased by a factor of approximately 6. Resistance to ketone-based solvents was proven and an increase in hardness was observed as the ratio of the inorganic part increased. Samples which contain 10% sol-gel content were observed to provide optimal properties.Publication Metadata only Wear, thermal, and physical properties of fluorine-containing polyimide/silica hybrid nanocomposite coatings(WILEY, 2019) AKIN, EMRE; Cakir, Mustafa; Akin, EmreThis study prepared fluorine and SiO2 particles containing organic-inorganic hybrid polyimide nanocomposite coatings (PISFs) with inorganic content in the range of 5-20% in pure polyimide solutions via the sol-gel process. Polyimide hybrid structures containing fluorine and SiO2 particles were synthesized by using perfluorooctyltriethoxysilane and tetraethyl orthosilicate. These formulations were applied on aluminum sheets by using a 75 mu m wire wound applicator, and the coatings were cured for 8 h at room temperature and then 24 h at 100 degrees C. Increased inorganic contents caused slight decreases in the initial decomposition temperatures, but the char yield values increased for PISF15 and PISF20. All samples exhibited hydrophobic properties. When all samples were compared, PISF5 and PISF10 exhibited hydrophobicity, high wear resistance and thermal properties. Additionally, PISF5 and PISF10 showed high adhesion, hardness, and methyl ethyl ketone solvent resistance. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47399.Publication Metadata only Coating properties of 1H,1H-perfluorooctylamine-terminated polyimides based on hexafluoroisopropylidene diphthalic anhydride and 1,4,5,8 naphthalenetetracarboxylic dianhydride(SPRINGER, 2019) AKIN, EMRE; Cakir, Mustafa; Akin, Emre; Artir, RecepThis study attempted to prepare polyimide coatings (PIs) containing 6FDA (hexafluoroisopropylidene diphthalic anhydride) and/or NTDA (1,4,5,8 naphthalenetetracarboxylic dianhydride) in various ratios. 1% of these polyimide chains were terminated with 1H,1H-perfluorooctylamine (PFOA) and PFOA, and terminated polyimide coatings (PIFs) were prepared in the same ratios as PIs. Coatings were produced on aluminum substrates by a 75-mu m wire-wound applicator and thermally imidized. Finally, thermal, wear, and physical properties of PIFs and PIs were compared to each other. PIFs exhibited higher abrasion resistance than PIs due to the presence of PFOA. The increase in 6FDA content also resulted in elevated abrasion resistance. Both NTDA and 6FDA compounds improved thermal stability. The increase in NTDA content raised the T-g values of the polyimides. PIFs exhibited higher static water contact angle values than PIs, but the existence of microcracks decreased their hydrophobicity. The gloss values of PIFs were excellent. Improved values were obtained for pencil hardness, crosscut adhesion, and MEK (methyl ethyl ketone) rubbing properties for all coatings. In addition to the pencil hardness test, a pendulum hardness test was also carried out. The presence of PFOA affected pendulum hardness values positively, and the increase in the amount of 6FDA on polymer backbone improved the pendulum hardness values despite the rigidity of NTDA.Publication Metadata only Synthesis and characterization of novel polyimidefor hydrofobic coating(2016-10-14) ÇAKIR, MUSTAFA; ARTIR, RECEP; AKIN E., ÇAKIR M., ARTIR R.