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YILDIZ, ZEHRA

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YILDIZ

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ZEHRA

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Now showing 1 - 5 of 5
  • Publication
    Preimpregnated natural fiber preforms
    (Elsevier Science, Oxford/Amsterdam , 2023-06-01) YILDIZ, ZEHRA; ERYILMAZ, OĞUZ; Yildiz Z., Eryilmaz O.
  • PublicationOpen Access
    Green photocurable phosphorus containing coatings on cotton fabrics
    (2023-08-01) YILDIZ, ZEHRA; Yildiz Z.
    In this work, a bio-based, lightweight, coated cotton fabric by using a cleaner manufacturing method, “photocuring” was proposed in order to be used as an alternative to the conventional heat-, solvent-, and waterbased outdoor textile (tarpaulin, tent, etc.) manufacturing. For this purpose, photocurable bio-based phosphorylated oligomer was synthesized with the reaction between a monomethacrylate functional phosphorus containing monomer and epoxidized soybean oil (ESBO). The synthesized phosphorylated ESBO (P-ESBO) oligomer was used in cotton fabric coatings in different proportions and photocured with UV light exposure. The effects of the amount of P-ESBO oligomer in the formulation on the crystalline morphology, mechanical, thermal, surface wettability, flammability, and abrasion resistance properties of the cotton fabrics were all searched. It was revealed that the increasing amount of P-ESBO oligomer in the formulation increases the drapeability and tensile strength of the fabrics with enhanced flame resist property by giving higher char yields. Besides, phosphorylated oligomer also acted as an adhesion promoter between the fabric surface and coating layer resulting a better abrasion resistance property.
  • Publication
    Mechanical and acoustic properties of alkali treated agricultural waste reinforced sustainable polyurethane composites
    (2023-11-01) KOÇAK, EMİNE DİLARA; YILDIZ, ZEHRA; KOÇAK E. D., Olcay H., YILDIZ Z.
    In this research, polyurethane (PU) foam composites were prepared by using various agricultural waste (rice husk, corn silk, artichoke stem) particles. In order to enhance the compatibility and adhesion between the waste particle and PU matrix, alkali treatment was employed. The alkali treated particles were chemically and morphologically characterized by Fourier transform infrared (FTIR) spectroscopy, cellulose determination instrument, and scanning electron microscopy (SEM), respectively. The effects of the alkali treatment on the structural, morphological, mechanical, and acoustic properties of the overall PU foam composites were all examined. Due to the differences in chemical compositions of the agricultural wastes, the alkali treatment affected the acoustic and mechanical properties of the PU foam composites in varying ratios. The PU foam composite reinforced with alkali treated artichoke stem waste particles showed the highest tensile strength value of 265 kPa, whereas the highest sound absorption value of 40.5% as an enhancement on the acoustic properties compared to the blank PU foam composite was recorded in corn silk waste particle loaded sample.
  • PublicationOpen Access
    Sustainable fabric printing by using pre-consumed cellulosic textile wastes: The effect of waste particle content
    (2024-04-05) YILDIZ, ZEHRA; KARTAL, İLYAS; KOÇAK, EMİNE DİLARA; ERYILMAZ, OĞUZ; YILDIZ Z., KARTAL İ., KOÇAK E. D., Ozer B., Kus B. N., ERYILMAZ O.
    The textile industry generates significant amounts of waste, including yarn/fiber fluffs, fabric scraps, offcuts, etc. These wastes can be recycled and repurposed for usage in screen printing which is a versatile and cost-effective printing technique by producing high-quality prints. In this study, pre-consumed colored cotton wastes were milled into 30–70 μm particle size by using a miller. Then the colored waste particles were included in a commercial printing paste and applied on cotton fabrics via screen printing. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, and energy dispersive spectrometer (EDS) were employed to observe the chemical changes in the printed textile fabrics. The printed fabrics were evaluated through color, wash/rub fastness, tensile strength, surface wettability, tactile, and air permeability properties. The dispersion quality of the waste particles on textile fabrics was observed by using light microscopy and scanning electron microscopy (SEM) images. The overall results demonstrate that a 10% amount of waste fibrous particle inclusion to the printing paste gave optimum results by means of dispersion quality of wastes, air permeability, and handle properties. Above 10% waste amounts, the waste particles cannot be dissipated well on the fabric surface, resulting in agglomerated and non-uniform printed areas. These findings hold substantial potential for promoting sustainable coloring applications by using colored pre-consumed textile wastes within the textile industry while maintaining high-quality fabric products.
  • PublicationOpen Access
    Usage of uv-curable soybean oil based coating formulations for pretreated cotton fabrics
    (2022-01-01) YILDIZ, ZEHRA; YILDIZ Z.
    This study aims to design an alternative way for the laminated fabric manufacturing with a cleaner production method, by using a bio-based coating formulation and time/cost saving, environmentally friendly UV-curing technology, compared to the conventional petroleum based, heat and solvent requiring laminating process. For this purpose, acrylated epoxidized soybean oil oligomer was synthesized and included in coating formulations for the application on cotton fabrics via UV-curing. The obtained oligomer was characterized by FTIR and NMR spectroscopies. In order to enhance the bonding between the fabric and coating layer, fabrics were pretreated by sodium hydroxide, pectinase enzyme, and a commercial washing agent prior to the coating process. The effects of pretreatment methods on the wettability, tensile and peel strength, and abrasion resistance of the fabrics were all examined before/after coating process. Enzyme pretreatment revealed promising results by increasing the surface roughness, fibrillation, and hydrophilicity of the cotton fabrics. After coating and UV-curing process, the highest increment in tensile strength, the highest peel strength, and the least weight loss value against abrasion were all recorded in enzyme pretreated fabric.