Browsing by Subject "Low density polyethylenes"

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    Elastic-plastic stress analysis and plastic zone propagation in fibre-reinforced thermoplastic laminates using finite element method
    (Technomic Publishing Co. Inc., 2001) Aykul H.; Atasi C.; Akbulut H.
    The results of a study of elastic-plastic stress analysis and plastic zone propagation in a low density polyethylene thermoplastic composite plate subjected to uniform transverse load are presented. Thermoplastic matrix, polyethylene (LDPE), and steel fibres were used to fabricate the composite plates. Yield points and elastic, elastic-plastic and residual stresses are calculated numerically for both symmetric and antisymmetric laminated plates with different ply orientations by using Finite Element Method. First order shear deformation theory was used as an equivalent single-layer laminate theory for small deformations. Contour plots corresponding to 100, 150 and 200 load steps display the expansion of the plastic zone. Mechanical properties of a layer were obtained experimentally.
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    Thermal and mechanical properties of LDPE by the effects of organic peroxides
    (John Wiley and Sons Ltd, 2017) Sirin K.; Cengel Ö.; Canli M.
    In this study, the effect of different organic peroxides on different types of low-density polyethylene (LDPE) was investigated. LDPE products like F2-21T, F5-21T, and I22-19T were mixed in different proportions with dialkyl peroxide, dibenzoyl peroxide, and dilauroyl peroxide. Melt flow rates, mechanical properties (tensile strength at yield, tensile strength at break, elongation at break, and stress-strain effect), thermal analysis (differential scanning calorimetric and thermogravimetric analysis), and scanning electron microscopy images of the prepared mixtures were examined. Cross-linking occurred in the structure of LDPE types having different molecular weight distribution by the addition of even small amounts of peroxide (e.g. 0–0.12 wt%). Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
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    Optimizing Optical and Structural Properties of Nanocomposites by ZnO and BP-3
    (Pleiades Publishing, 2018) Türemiş M.; Keskin I.Ç.; Katı M.I.; Kibar R.; Şirin K.; Çanlı M.; Çorumlu V.; Çetin A.
    This study aims to find out usage of zinc oxide (ZnO) and 2-hydroxy-4-methoxybenzophenone (BP-3) for getting better optical and structural properties of nanocomposites. Polymer nanocomposites were prepared by adding zinc oxide for minimizing UV rays effects of the sun with the particle size of nanometer in different ratios to a low density polyethylene (LDPE). The polymer mixtures were synthesized by mixing nanocomposite samples with BP-3 featuring UV stabilizer. Besides making tensile testing measurements, in order to find out the optical, structural, mechanical and thermal changes, the new polymer nanocomposites were characterized by XRD, TG-DTA spectra, and SEM images. The samples with zinc oxide which show luminescent properties were examined in terms of radioluminescence features. Radioluminescence spectrum showed characteristic peaks of zinc oxide dispersed nanocomposites prepared with LDPE. The intensity of the characteristic peaks at 530 and 390 nm (exciton) increased by increasing rates of nanopowder zinc oxide while adding BP-3 to the composites caused a decrease in intensity of radioluminescence. © 2018, Pleiades Publishing, Ltd.