Yazar "Tasdelen, Mehmet Atilla" seçeneğine göre listele

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    Antibacterial film from chlorinated polypropylene via CuAAC click chemistry
    (Elsevier Science Bv, 2018) Acik, Gokhan; Altinkok, Cagatay; Olmez, Hulya; Tasdelen, Mehmet Atilla
    Polypropylene possessing quaternary ammonium salt (PP-QAS) is synthesized by copper (I)-catalyzed azide-alkyne cycloaddition "click" reaction (CuAAC) starting from chlorinated polypropylene (PP-Cl). The antibacterial properties of PP-QAS have been investigated on gram-positive (Staphylococcus aureus) and gram-negative (Escherichia colt) bacteria. For this purpose, clickable azide functionality has been introduced into PP-Cl backbone by using azidotrimethylsilane (TMS-N-3) - tetrabutylammonium fluoride solution (TBAF) system in tetrahydrofuran (THF) (PP-N-3). Independently clickable alkyne functionalized QAS is prepared by the reaction between 3-dimethylamino-1-propyne and benzyl bromide in the presence of triethyl amine (TEA). Finally, the polypropylene film containing quaternary ammonium salt (PP-QAS) is prepared by the successive CuAAC click reaction and solution casting method. The preparation of PP-QAS is monitored by fourier transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (H-1-NMR), differential scanning calorimetry (DSC) and scanning electron microscope (SEM) analyses at various stages. Based on antibacterial activity experiments, the PP-QAS coupons significantly inhibit both the growth of S. aureus and E. coli (p < 0.05) compared to neat PP-CI and control samples.
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    Cysteamine-functionalized silver nanowires as hydrogen donor for type II photopolymerization
    (Elsevier Science Sa, 2017) Altinkok, Cagatay; Oytun, Faruk; Basarir, Fevzihan; Tasdelen, Mehmet Atilla
    A versatile method for the in-situ preparation of poly(methyl methacrylate)/silver nanowire (PMMA/AgNW) nanocomposites has been reported. The use of cysteamine-functionalized silver nanowires as hydrogen donors in type II photopolymerization enables us to fabricate PMMA/AgNW nanocomposites under mild conditions such as ambient temperature and solvent-free formulation. The morphology of nanocomposites is investigated by using scanning electron microscopy and compared by a solution mixing sample that prepared identical experimental condition. The distribution of AgNWs in the in-situ prepared nanocomposite is much homogenous than the solution mixing sample. The results from thermogravimetric analysis and differential scanning calorimetry clearly indicated that thermal behaviour of the nanocomposites is slightly improved than that of neat PMMA. (C) 2017 Elsevier B.V. All rights reserved.
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    Synthesis and characterization of bile acid-based polymeric micelle as a drug carrier for doxorubicin
    (Wiley, 2021) Altinkok, Cagatay; Acik, Gokhan; Karabulut, Huseyin Riza Ferhat; Ciftci, Mustafa; Tasdelen, Mehmet Atilla; Dag, Aydan
    In the present study, a polymeric micelle based on amphiphilic block copolymer, namely poly(methacrylated methyl lithocholate)-block-poly(oligoethylene glycol methacrylate) (PMML-b-POEGMA) bearing bile acid moiety is prepared via sequential photo-initiated free radical polymerizations, and its drug carrying capacity is investigated using doxorubicin hydrochloride (DOX) as a model drug. For this purpose, two-step procedure is applied in the presence of phenylbis (2,4,6-trimethylbenzoyl)phosphine oxide (BAPO) as bifunctional photo initiator. Based on spectroscopic and chromatographic analyses, the desired amphiphilic block copolymer (PMML-b-POEGMA) is successfully synthesized by wavelength-selective free radical photopolymerization under mild conditions. Finally, the DOX drug is loaded into the PMML-b-POEGMA micelles and then drug release behavior is investigated at two different pH (5.5 and 7.4) values. It is concluded from the results that PMML-b-POEGMA micelles may be used as an efficient nanocarrier to deliver conventional anti-cancer drugs for combination chemotherapy.
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    Synthesis and characterization of polypropylene-graft-poly(l-lactide) copolymers by CuAAC click chemistry
    (Wiley, 2018) Acik, Gokhan; Altinkok, Cagatay; Tasdelen, Mehmet Atilla
    The syntheses of polypropylene-graft-poly(l-lactide) copolymers (PP-g-PLAs) via copper (I)-catalyzed azide-alkyne cycloaddition "click" reaction (CuAAC) using azide side-chain functionalized polypropylene (PP-N-3) and alkyne end-functionalized poly(l-lactide) (PLA-Alkyne) were reported. The CuAAC was then applied to azide and different feeding ratios of alkyne functional polymers to give PP-g-PLAs that were characterized by FTIR, H-1-NMR, GPC, DSC, and WCA measurements. The CuAAC click reaction was achieved by two different feeding ratio (PP-N-3:PLA-Alkyne = 1:5 and 1:10) and thermal, biodegradable, and surface properties of obtained graft copolymers were investigated. The molar ratio of PLA were calculated as 72.7 (PP-g-PLA-1) and 78.4% (PP-g-PLA-2) by H-1-NMR spectroscopy. The water contact angle (WCA) values of PP-g-PLA-1 (81(o) +/- 1.3) and PP-g-PLA-2 (75(o) +/- 1.6) copolymers were compared with commercial chlorinated polypropylene (PP-Cl) (90(o) +/- 1.0), suggesting a more hydrophilic nature of desired graft copolymers produced. Conversely, the enzymatic biodegradation studies revealed that the weight losses of graft copolymers were determined as 13.6 and 22.1%, which is about 4% for commercial PP-Cl sample. Thus, it was clear that this simple and facile method was effective in promoting biodegradation of commercial polypropylene and attractive particularly for worldwide environmental remediation goals. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2595-2601
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    Synthesis and Properties of Soybean Oil-based Biodegradable Polyurethane Films
    (ELSEVIER SCIENCE SA, 2018) Acik, Gokhan; Kamaci, Musa; Altinkok, Cagatay; Karabulut, H. R. Ferhat; Tasdelen, Mehmet Atilla
    In this study, a series of biodegradable polyurethane films (PU-Fs) is prepared by step-growth polymerization of hydroxylated soybean oil (SBO-OH) and L-lysine diisocyanate ethyl ester (L-LDI) that are renewable-based di-functional building blocks. The influence of loading ratio by weight (SBO-OH/L-LDI (w/w) = 1:0.5; 1:1 and 1:1.5) on the biodegradable, mechanical and thermal properties of final PU-Fs is systematically investigated. In the first step, epoxy groups of epoxidized soybean oil are converted to corresponding hydroxyl functionalities to react with the diisocyanate groups of L-LDI via film casting method at room temperature. The obtained PU-Fs with higher L-LDI loading exhibit higher thermal and mechanical properties as well as more hydrophobic characteristic compared to others. Moreover, biodegradability of resulting PU-Fs is also studied using hydrolytic and enzymatic degradation experiments. Noteworthy, it is found that around 50 and 60% of PU-Fs are degraded by enzymatic and hydrolytic experiments after 12 weeks.