Person: YILDIZ, ZEHRA
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YILDIZ
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ZEHRA
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Publication Metadata only Effects of NCO/OH Ratio and Reactive Diluent Type on the Adhesion Strength of Polyurethane Methacrylates for Cord/Rubber Composites(TAYLOR & FRANCIS INC, 2018) YILDIZ, ZEHRA; Yildiz, Zehra; Onen, Hacer Aysen; Gungor, Atilla; Wang, Youjiang; Jacob, KarlA series of dual curable polyurethane methacrylate-based oligomers were synthesized by changing the NCO:OH ratio and then were included in adhesive formulations using trimethylolpropane trimethacrylate and tricyclodecane dimethanol diacrylate (TCDDA) as reactive diluents. The effects of NCO:OH ratio and reactive diluent type on the structural properties of UV-cured free films and adhesion properties between polyester cord/rubber surfaces were studied. The highest adhesion strength of the 103Ncm(-1) was obtained when the NCO:OH ratio was set as 4 and the TCDDA was used as a reactive diluent. [GRAPHICS] .Publication Metadata only Chemical, mechanical, and thermal properties of UV-curable cellulose acetate butyrate-based oligomers and their electrospun fibrous mats(SPRINGER, 2020) YILDIZ, ZEHRA; Dehmen, Ozan Gazi; Onen, Hacer Aysen; Yildiz, Zehra; Gungor, AtillaIn this research, toluene diisocyanate-2-hydroxyethyl methacrylate (TDI-HEMA) adduct was used to modify the hydroxyl groups on cellulose acetate butyrate (CAB) structure. The obtained oligomer was characterized by Fourier transform infrared and proton nuclear magnetic resonance (H-1 NMR) spectroscopies, and gel permeation chromatography, respectively. Then, the UV-cured free films of the modified CAB oligomers were investigated in terms of thermal degradation, physicochemical, wettability, and mechanical properties. The chemical modification process was performed in various percentages; then, the contribution of the unreacted hydroxyl groups of CAB on the wettability, thermal degradation, and air/water vapor permeability properties were all investigated. The mechanical properties, thermal stability, and surface wettability character of pure CAB were improved with TDI-HEMA adduct modification. Electrospinning was used to obtain a fibrous layer in order to search the air/water vapor permeability properties. Modification of CAB caused decline in air/water vapor barrier character and thus enhanced the permeability properties.Publication Metadata only The preparation of UV-cured superhydrophobic cotton fabric surfaces by electrospinning method(SAGE PUBLICATIONS LTD, 2014) KARTAL, İLYAS; Cakir, Mustafa; Kartal, Ilyas; Yildiz, ZehraElectrospinning was used for the coating of the polyurethane/silica hybrid solutions on the cotton fabric surface. An ultraviolet curing process was performed on the collector by an ultraviolet lamp positioned inside the electrospinning cabin. In order to investigate the effect of fluorinated, silane-functionalized urethane (inorganic part) content on the water-repellency; five different fluorinated concentrations (10%, 20%, 30%, 40%, and 50% by weight) were used. The disappearance of isocyanate peaks during the silane-functionalized urethane synthesis was observed by Fourier transform infrared spectroscopy. Surface morphology and elemental analysis of the coated cotton fabric surfaces was investigated by scanning electron microscopy and energy dispersive spectroscopy analysis respectively. Water-repellency was evaluated by contact angle measurements. A sample that contained 50% inorganic part showed a contact angle of 154.5 degrees. Samples were thermally characterized by differential scanning calorimetry. Glass transition temperature of the synthesized hybrid polymer increased with increasing inorganic part ratio. Additionally, abrasion resistance and crease recovery angle tests were performed to evaluate the effect of fluorinated part percentage on the mechanical and comfort properties of fabrics.