Person: ÇAKMAKÇI, EMRAH
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ÇAKMAKÇI
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EMRAH
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Publication Metadata only Quaternary imidazolium-functionalized reactive silica nanoparticles-containing thiol-ene photocured antibacterial hybrid coatings(Elsevier B.V., 2022) ÇAKMAKÇI, EMRAH; Şen F., Kocatürk E., Çakmakçı E., Kahraman M.V.The need for antibacterial coatings is increasing day by day. In this study, coating materials that do not contain antibacterial agents but have antibacterial properties have been developed. First, two different quaternary imidazole compounds were synthesized. Then, silica nanoparticles were modified with these quaternary agents. By using 1%, 3% and 5% modified silica nanoparticles, UV cured coating materials were obtained according to the thiol-ene reaction mechanism. Mechanical, thermal, surface, structural, optical and antibacterial analyzes of the obtained coatings were performed. The analyzes revealed that UV cured antibacterial coating materials have been successfully synthesized and can be used as a new and unique coating material for the coating industry. © 2021 Elsevier B.V.Publication Open Access Eugenol-DOPO: A bio-based phosphorous-containing monomer for thiol-ene photocurable thermosets(2023-01-01) ÇAKMAKÇI, EMRAH; Özükanar Ö., ÇAKMAKÇI E., Sagdic G., Günay U. S., Durmaz H., Kumbaracı İ. V.The adverse health and environmental effects of petroleum-based materials have become a driving force for the fabrication of bio-based monomers. In this study, we synthesized a novel bio-based reactive phosphorus-containing; eugenol-DOPO, which was prepared in one step by the reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and eugenol via Atherton–Todd reaction. Moreover, a diallyl compound was also prepared by using eugenol and piperazine. All monomers were characterized by nuclear magnetic resonance (NMR), mass, and Fourier-transform infrared (FTIR) spectroscopies. Thiol-ene photocured polysulfide thermoset networks were prepared by using these newly synthesized bio-based monomers. Thermal and thermomechanical properties of the thermosets were measured. Photo-crosslinked networks displayed over 88% gel content values. The thermal stability of the networks as well as the resulting char yields were improved as the percentage of eugenol-DOPO was increased in the formulations. The presence of N and P played a synergistic effect and the limiting oxygen index (LOI) values for the thermoset materials were enhanced. We believe eugenol-DOPO is not only a good alternative monomer for the preparation of thermally stable photocurable thermosets, but it is also a suitable bio-based additive for other polymers as well. Graphical Abstract: [Figure not available: see fulltext.].Publication Open Access Metal-free click modification of triple bond-containing polyester with azide-functionalized vegetable oil: plasticization and tunable solvent adsorption(2022-07-12) ÇAKMAKÇI, EMRAH; Cangul K., ÇAKMAKÇI E., Daglar O., Günay U. S., Hızal G., Tunca Ü., Durmaz H.Pressure from environmental nongovernmental organizations and the public has accelerated research on the development of innovative and renewable polymers and additives. Recently, biobased \"green\" plasticizers that can be covalently attached to replace toxic and migratory phthalate-based plasticizers have gained a lot of attention from researchers. In this work, we prepared an azide-functionalized soybean oil derivative (AzSBO) and investigated whether it can be used as a plasticizer. We covalently attached AzSBO to an electron-deficient triple-bond-containing polyester via a metal-free azide-alkyne click reaction. The thermal, mechanical, and solvent absorption behaviors of different amounts of azidated oil-containing polyesters were determined. Moreover, the plasticization efficiency of AzSBO was compared with the commercial plasticizers bis(2-ethylhexyl) phthalate and epoxidized soybean oil. At relatively lower AzSBO ratios, the degree of cross-linking was higher and thus the plasticization was less pronounced but the solvent resistance was significantly improved. As the ratio of AzSBO was increased, the glass transition temperature of the pristine polymer decreased up to 31 degrees C from 57 degrees C. Furthermore, the incorporation of AzSBO also improved the thermal properties and 20% AzSBO addition led to a 60 degrees C increase in the maximum weight loss temperature.Publication Metadata only New horizon in phospha-michael reaction: Ultrafast double addition of P-H bond-bearing nucleophiles to alectron-deficient triple bonds and its use for functional monomer synthesis and polymer modification(2023-01-01) ÇAKMAKÇI, EMRAH; FINDIK, VOLKAN; ERDEM, SAFİYE; Sagdic G., Daglar O., ÇAKMAKÇI E., FINDIK V., ERDEM S., Tunca Ü., Günay U. S., Durmaz H.In this work, a novel, straightforward, robust, fast, and organocatalyst-mediated phospha-Michael reaction (OCPMR) was developed for the addition of phosphorus nucleophiles to electron-deficient alkynes. Several P-H bond-bearing compounds with either fully aliphatic or aromatic units were utilized for this newly developed reaction, and it was found that phosphorous species containing only aromatic groups reacted with activated alkynes within 5 min at room temperature. The reaction led to a fast double-addition of the phosphorous compounds to the triple bond of the alkynes. An in-depth analysis of the reaction mechanism and selectivity of this OCPMR was performed using computational methods. Using the developed method, double-phosphorylated allyl-functional monomers were synthesized and subsequently used for the synthesis of linear and crosslinked polymers via thiol-ene photopolymerization. The thermoset materials exhibited LOI values as high as 26.4%. We also showed that polyesters having electron-deficient triple bonds could be easily functionalized with the P-H bond-bearing compounds. The synthetic method proposed herein promises easy and fast P-C bond formation under mild reaction conditions, and it is a straightforward method for the synthesis of phosphorus-containing monomers, linear or crosslinked polymers, and for polymer post-functionalization. We believe this feature will be of great interest not only to material chemists and polymer scientists but also to organic chemists, pharmaceutical researchers, etc.Publication Metadata only Dimer diamin ve hint yağı esaslı bio-bazlı poliüretan köpük ve hint yağı esaslı alev geciktirici hazırlanması(2022-09-01) ÇAKMAKÇI, EMRAH; KAHRAMAN, MEMET VEZİR; Nasuhoğlu B., ÇAKMAKÇI E., KAHRAMAN M. V.Diizosiyanat ve diollerin reaksiyonu sonucu elde edilen poliüretanlar, günlük hayatımızda geniş bir kullanım alanına sahip polimerlerin başında gelmektedir. Üretilen bu ticari poliüretanlar petrol kaynaklı malzemeler kullanılarak sentezlenir[1]. Petrolün yenilenebilir bir kaynak olmamasından dolayı ve gün geçtikçe petrol fiyatlarının artmasına bağlı olarak, bu tip malzemelerin üretim fiyatının düşürülmesi ve fosil yakıtlara bağımlılığın azaltılması için polimer sentez çalışmalarında yenilebilir kaynakların kullanılması hem ekonomik hem de çevresel açıdan önemlidir. Poliüretan ham maddelerinden poliol sentezinde kullanılan yenilenebilir kaynakların başında, sentetik kimyaya en uygun malzemelerden olan bitkisel yağlar gelmektedir[2]. Bu bitkisel yağlardan yüksek doymamışlığa sahip hint yağı, keten yağı, tung yağı, ayçiçek yağı ve soya yağı bu tür çalışmalarda sıklıkla tercih edilir. Bu çalışmada, petrokimyasalları mümkün olan en az miktara indirmek amacıyla, dimer diamin ve hint yağı kullanılarak otokatalitik poliol ve hint yağı kullanılarak alev geciktirici sentezi yapılmıştır. Sentezlenen monomerler, FTIR tekniğiyle karakterize edilmiştir ve elde edilen köpüklerin mekanik testleri yapılmıştırPublication Open Access Thermal and mechanical properties of thiol-ene photocured thermosets containing DOPO-based liquid reactive flame retardant synthesized by metal-free azide-alkyne click reaction(2022-06-01) ÇAKMAKÇI, EMRAH; Sagdic G., ÇAKMAKÇI E., Daglar O., Günay U. S., Hızal G., Tunca Ü., Durmaz H.The use of metal-free click reactions for the design and synthesis of novel flame retardant reactive monomers for thiol-ene photopolymerization is an intriguing area of research. In this study, we have prepared a new, 9,10-dihy-dro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based, P-and N-containing reactive flame retardant via the metal-free azide-alkyne click reaction. For this purpose, first, azide-functionalized DOPO (DOPO-N-3) has been synthesized via Atherton-Todd reaction, and then this compound has been reacted with acetylene dicar-boxylic acid diallyl ester (ACDAE) to give the flame retardant monomer, namely DOPO-triazole diallyl ester (DTDAE). As prepared flame retardant monomer was characterized by nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR) spectroscopies. Thermoset materials prepared by using DTDAE displayed over 90% gel content values. Polar triazole and phosphorous units rendered the surface of the ther-mosets hydrophilic. The thermal stability of the networks was enhanced, char yields increased and the glass transition temperatures (T(g)s) were increased. The limiting oxygen index (LOI) values of the crosslinked materials increased up to 27.8% as the DTDAE content was increased in the formulations. The synthetic method described in this study provides a practical approach for the synthesis of a P-and N-containing flame retardant through a metal-free azide-alkyne click reaction Also, the fact that DTDAE is in a liquid state makes this study valuable as it indicates that it can be easily dispersed. It is also believed this promising compound can be used in different polymer structures and formulations to develop new flame retardants in future studies to be applied in industrial applications.Publication Open Access Immobilization of acetylcholinesterase onto pyrrole-containing photocured thermosets(2023-04-01) DEMİR, SERAP; ÇAKMAKÇI, EMRAH; OGAN, AYŞE; ALI K. K., DEMİR S., ÇAKMAKÇI E., OGAN A.Acetylcholinesterase (AChE; EC 3.1.1.7) is a group of enzymes that catalyzes the hydrolysis of the neurotransmitter acetylcholine (ACh) into choline and acetate. AChE inhibition is commonly utilized as a biomarker for pesticides. In membrane based AChE biosensors the enzyme immobilization onto an electrode surface is of prime importance. In previous studies, conducting polymers-based supports have been used for the immobilization of AChE. In this study, a novel immobilization platform was developed. The simultaneous polymerization of pyrrole and functional thiol/ene monomers was performed to prepare conductive thermosets. AchE was covalently immobilized onto the membranes through the epoxy functional groups. After the immobilization process, the optimal temperature increased to 50 °C, displaying a better thermal stability and the optimum pH was elevated to 8.5. The activity of the immobilized enzyme was tested in the presence of several metals, and it was found that Cu2+ ions caused a noticable inhibition. After 10 cycles, the immobilized enzyme retained 51% of its original activity. In accordance with our results; the durability and the stability of the immobilized enzyme were improved. In future studies, the method applied here can be used in the design of an AchE biosensor.Publication Open Access Thiol-ene photopolymerization meets azide-alkyne click reactions: P/N/Si-containing, dual curable eugenol-based hybrid coatings(2023-08-17) ÇAKMAKÇI, EMRAH; Özükanar Ö., ÇAKMAKÇI E., Daglar O., Durmaz H., Kumbaracı İ. V.The use of bio-based building blocks for the synthesis of polymers is increasing day by day. Among the bio-based building blocks, eugenol is a highly promising monomer for the preparation of thermoset materials. In this study, we combined thiol-ene photopolymerization (TEP) and thermal azide-alkyne cycloaddition click reactions to prepare eugenol-based thermally stable, P-, N-, and Si-containing networks. To this end, we synthesized a P-containing, eugenol-based monomer bearing azide group and a siloxane compound containing an alkyne group. By mixing these monomers with multifunctional thiols and by utilizing a dual-curing strategy, we managed to obtain optically transparent and thermally stable coatings with excellent adhesion to glass substrates. Thermal stability, optical transmittance, pendulum hardness, solvent resistance, and the adhesion performance of the coatings were evaluated. The gel contents of the thermoset materials were found to be over 95%. At 600 °C, the char yields of the dual-cured coatings were found to be over 30%. Coatings were also found to be resistant to acidic and basic conditions as well as solvents.Publication Metadata only Acetylene Dicarboxylic Acid Diallyl Ester: A Versatile Monomer for Thiol-Ene Photocured Networks(WILEY-V C H VERLAG GMBH, 2021) ÇAKMAKÇI, EMRAH; Daglar, Ozgun; Cakmakci, Emrah; Gunay, Ufuk Saim; Hizal, Gurkan; Tunca, Umit; Durmaz, HakanThiol-ene photopolymerization (TEP) is a highly advantageous method for the curing of unsaturated monomers, and the design of novel monomers to be used in TEP is an active area of research. The feasibility and the versatility of novel acetylene dicarboxylic acid diallyl ester (ACDAE)-based monomers are synthesized and demonstrated. The electron deficient acetylenic core in ACDAE allows to apply three different click reactions, aza-Michael, thio-Michael, and metal-free azide-alkyne cycloaddition reactions, efficiently on it. Thus, three novel allylic monomers are synthesized and are used to prepare thiol-ene photopolymerized networks. All monomers are synthesized in good yields and structurally characterized by H-1 NMR and Fourier-transform infrared spectroscopy (FTIR) measurements. Thermal, thermomechanical, and mechanical properties, flame retardancy, transmittance, and the wettability of the networks are determined.Publication Metadata only Practical phosphorylation of polymers: an easy access to fully alcohol soluble synthetically and industrially important polymers(ROYAL SOC CHEMISTRY, 2021) ÇAKMAKÇI, EMRAH; Sagdic, Gokhan; Daglar, Ozgun; Gunay, Ufuk Saim; Cakmakci, Emrah; Hizal, Gurkan; Tunca, Umit; Durmaz, HakanPhosphorus-containing polymers have always been privileged structures in polymer science due to the widespread use of these polymers in various fields, particularly in bio-related applications. It is therefore of utmost importance to endow synthetic and industrial polymers with phosphorus units not only to enlarge their potential use in bio-related applications, but also to improve the ease of processing and operation simplicity for various applications. In this study, we report a facile method to synthesize polymers with phosphorus pendant groups. A commercial compound, namely bis(diethoxyphosphoryl) acetylene, where a triple bond is bonded to two phosphodiester (PvO(OC2H5)(2)) units was reacted with various azide-functionalized synthetically and industrially important polymers, such as polystyrene (PS), polyester (PE), polyurethane (PU), polycarbonate (PC), polyvinyl chloride (PVC), and polyepichlorohydrin (PECH), in a green solvent, 2-methyltetrahydrofuran (MeTHF), through metal-free azide-alkyne 1,3-dipolar cycloaddition reactions. It was found that all the phosphorylated polymers became soluble in a variety of alcohols due to the contribution of phosphodiester units. Moreover, the thermal properties of the phosphorylated polymers were analyzed and significant enhancements in thermal stabilities were found compared with their phosphorus-free precursors. Since phosphorylation of synthetically and industrially important polymers is a long-standing demand in polymer chemistry, suffering from the lack of a general synthetic route, the proposed method offers a green, practical, and robust solution to this aim.
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