Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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2006 - 200912010 - 20121

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Has files: YesSubject: search.filters.subject.Polymeric composites--Mechanical properties

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  • Master Thesis
    Mechanical and Thermal Properties of Non-Crimp Glass Fiber Reinforced Composites With Silicate Nanoparticule Modified Epoxy Matrix
    (Izmir Institute of Technology, 2006) Bozkurt, Emrah; Tanoğlu, Metin
    In the present study, epoxy based nanocomposites were prepared with modified and unmodified silicate nanoparticules to apply as a matrix resin for non-crimp glass fiber reinforced polymer composites. The effects of the silicate nanoparticules on the mechanical, thermal and flame retardancy properties of glass reinforced composites were investigated. Laminates were manufactured with hand lay-up technique and cured under compression. To intercalate the layers and obtain better dispersion of silicate layers within the matrix, silicate (montmorillonite, MMT) particules were treated with hexadecyltrimethylammonium chloride (HTAC) surfactants. X-ray diffraction of silicates with and without surface treatment indicated that intergallery spacing of layered silicate increased with surface treatment. Tensile tests showed that silicate loading had minor effect on the tensile strength and modulus of the composite laminates. Flexural properties of laminates were improved with the addition of silicate due to the improved interface between glass fibers and epoxy matrix. With the addition of modified MMT (OMMT), interlaminar shear strength (ILSS) of laminates decreased slightly but fracture toughness (KIC) of laminates were increased. The fracture surfaces were examined with scanning electron microscopy (SEM) and the results revealed that fracture mechanisms were altered due to the presence of silicates in the matrix. Differential scanning calorimetry (DSC) results showed that modified silicate particules increase the glass transition temperatures (Tg) of composite laminates. Incorporation of OMMT particules increased the dynamic mechanical properties of non-crimp glass fiber reinforced epoxy composites. It was found that the flame resistance of composites was improved due to silicate particule additions into the epoxy matrix.
  • Master Thesis
    The Effects of Diatom Shape and Heat Treatment on the Mechanical Properties of Diatom-Frustule Polymeric Matrix Composites
    (Izmir Institute of Technology, 2012) Zeren, Doğuş; Güden, Mustafa
    The effects of diatom frustule shape and heat treatment process on the compressive mechanical properties of an epoxy matrix were experimentally investigated. Different pennate diatoms reduced to exclusive species by isolating and culturing were used as filler in the epoxy matrix. A commercial diatomite was heat treated between 600oC and 1200oC to increase the crystallinity. Filling epoxy matrix with ~6 wt% of natural commercial diatomite and Achnanthes taeniata frustule increased the compressive strength from 60 MPa to 67 MPa and 79 MPa, respectively. A higher strengthening, ~10 MPa, and moduli with Achnanthes taeniata frustule addition was found. The heat treatment of natural diatomite frustules at 1000oC increased both compressive strength and stress values of the epoxy matrices. The compressive strength increased from 60 to 90 MPa with the heat-treatment process, providing 50% of increase in the compressive strength of neat epoxy.