Yazar "Koytepe, S" seçeneğine göre listele

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    Polyimides from a novel monomer 3,6-bis(dimethylamino) acridine(p-cymene)dichlororuthenium(II) for a catalytic application
    (Springer, 2004) Seckin, T; Koytepe, S; Özdemir, I; Gürbüz, N; Çetinkaya, B
    Tricyclic heteroaraomatic dye-based monomer containing NMe2 units, 6-bis(dimethylamino)acridine(p-cymene)dichlororuthenium (II), was used to prepare novel polyimides via a one-stage solution polycondensation due to their stability under a variety of oxidative and reductive conditions. The Ru(II) complex monomer was synthesized starting from [RuCl2(p-cymene)](2) and 3,6-bis(dimethylamino)acridine. A series of stable polyimides was synthesized from the Ru(II) complex of 3,6-bis(dimethylamino)acridine and various aromatic dianhyrides. The polymers had inherent viscosities ranging from 1.72 to 2.11 dL/g and were soluble in polar solvents. The glass transition temperatures were 192-278degreesC, and the 10% weight loss temperatures were above 503-635degreesC. Ruthenium-substituted polyimides were tested for catalytic activity in the furan formation reaction of (Z)-3-methylpent-2-en-4-yn-1-ol. The polymeric catalyst was added to (Z)-3-methylpent-2-en-4-yn-1-ol without a solvent and the pure furan was isolated by distillation under reduced pressure. The conversion of the starting, enynol, was determined by gas chromatography (GC).
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    Syntheses and properties of metal containing polyimides based on the gold carbene complex
    (Springer, 2003) Seckin, T; Koytepe, S; Ozdemir, I; Çetinkaya, B
    A novel gold carbene complex, bis(1,3-di-p-dimethylaminobenzylimidazolidinylidene) gold(I), was synthesized and polymerized to polyimides in a one-step method with various aromatic dianhyrides. The gold-coordinated polyimides are characterized by IR and NMR (H-1, C-13) spectroscopy. The materials have inherent viscosities that range from 1.88 to 2.39 dl/g and show excellent solubility in N-methylpyrrolidone and N,N-dimethylacetamide. The glass transition temperatures of the coordinated polyimides range from 203-265degreesC and a 5% weight loss in air is observed from 535-578degreesC. The polymers form dark yellow, tough films that are transparent above 365 nm. The effect of different flexible units on the properties of the polyimides is discussed.
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    Synthesis and characterization of novel polyimides starting from 1,2-bis(p-dimethylaminobenzylideneimino)alkane homologues and various dianhydrides
    (Wiley, 2004) Koytepe, S; Gök, Y; Alici, B; Seçkin, T; Çetinkaya, E
    The objective of this research was the preparation of polyimides from 1,2-bis(p-dimethylaminophenylimino)alkane homologues and various dianhydrides in N-methylpyrrolidone by one-stage polycondensation. The monomers were prepared via condensation of p-dimethylaminobenzaldehyde and the corresponding diamines, 1,4-diaminobutane, 1,3-diaminopropane and 1,2-diaminoethane. The influence of the incorporation of this moiety into the polymer backbone on the properties of the polyimides has been evaluated. The thermogram of the polyimides indicated that PI-10 to PI-32 had T-g values ranging from 181 to 290degreesC. The inherent viscosities of the polymers ranged from 0.99 to 2.05 dl g(-1), and the highest solubility was obtained without significant loss of the thermal properties. (C) 2004 Society of Chemical Industry.