The Experts below are selected from a list of 57 Experts worldwide ranked by ideXlab platform

Fawaz Deri - One of the best experts on this subject based on the ideXlab platform.

  • Melt Rheology of Poly(Lactic Acid)/Low Density Polyethylene Polymer Blends
    Advances in Chemical Engineering and Science, 2011
    Co-Authors: Kotiba Hamad, Mosab Kaseem, Fawaz Deri
    Abstract:

    In this work, rheological properties of poly (lactic acid) (PLA), low density Polyethylene (LDPE) Polymer blends were investigated in the molten state. The experiments were carried on a capillary rheometer. The effect of shear stress, temperature and blending ratio on the flow activation energy at a constant shear stress and melt viscosity of the blends are described. The results showed that the PLA/LDPE Polymer blends are pseudo plastic in nature, where there viscosity decreases with increasing shear stress. Also it was found the melt viscosity of the blends decreases with increasing PLA content in the blend

Weiqiang Liu - One of the best experts on this subject based on the ideXlab platform.

  • insight on the mechanical and tribological characteristics of ball on socket artificial disc under alternate motion of flexion extension axial rotation and lateral bending axial rotation
    Journal of Materials Engineering and Performance, 2021
    Co-Authors: Song Wang, Dingding Xiang, Jian Song, Zhenhua Liao, Weiqiang Liu
    Abstract:

    Ball-on-socket articulation is the major structural type of artificial joints. The insight on the mechanical and bio-tribological characteristics of this structure is important for designing both the device itself and its wear assessment regime. Two kinds of ball-on-socket structures were studied including a simplified general model and a real artificial cervical disc. The bio-tribological behaviors were evaluated by in vitro wear simulation method using four kinds of pairs with different combinations of structure, frictional material and testing duration under alternate motion of FE-AR (flexion extension and axial rotation) and LB-AR (lateral bending and axial rotation). In order to analyze the formation mechanism of representative wear characteristics, the mechanical behaviors were also studied by finite element analysis method. The results indicated that there were similar mechanical and bio-tribological characteristics for these two structures after about 9 MC (Million Cycles) tests. Under the axial load, it revealed more serious wear severity in the edge region than that in the central region for both convex Polymer component and concave metal component, which may be due to much higher values of equivalent stress and equivalent elastic strain in the edge region than that in the central region. Under FE (flexion extension) or LB (lateral bending) motion, it showed common wide and curved wear grooves with ring distribution in the edge region for both ball component and nucleus pulposus component, which may be attributed to the higher equivalent stress and equivalent elastic strain at the limit position. It just indicated several sliding scratches for TC4 (Ti6Al4V alloy) metal component with an abrasive wear mechanism, while it revealed plastic deformation, surface cracks, sliding scratches and wear grooves for XPE (crosslinking Polyethylene) Polymer component with a mix of abrasive wear and adhesive wear mechanism. Hence, there was a strong correlation between structural design and bio-tribological characteristics for ball-on-socket prostheses.

Hiroki Kondo - One of the best experts on this subject based on the ideXlab platform.

  • Interaction of oxygen with polystyrene and Polyethylene Polymer films: A mechanistic study
    Journal of Applied Physics, 2020
    Co-Authors: Yusuke Fukunaga, Roberto C. Longo, Peter L. G. Ventzek, Barton Lane, Alok Ranjan, Gyeong S. Hwang, Gregory Hartmann, Takayoshi Tsutsumi, Kenji Ishikawa, Hiroki Kondo
    Abstract:

    In this work, first principles calculations combined with advanced surface diagnostics are used to unravel the mechanisms of plasma oxygen interaction with organic films of interest for advanced patterning in semiconductor device manufacturing. Results from a combination of x-ray photoelectron spectroscopy (XPS) diagnosed oxygen plasma exposed polystyrene films and first principles modeling of organic films (polystyrene, Polyethylene, and derivatives) provide insights into how organic films are oxidized by oxygen atoms. XPS measurements show the rapid formation of C-O structures and their saturation after oxygen exposure on both pristine and argon bombarded polystyrene samples. Quantum mechanics calculations confirm that C-OH formation can be immediate without recourse to previously formed dangling bonds. Multiple oxygen impacts are required for scission of pristine ethylene carbon strands. Therefore, ethylene films can be converted to polyols that are stable, whereas more likely strands are broken before polyol formation through the formation of water and C=O. On the contrary, intermediate compounds with adjacent C=O bonds are not likely to form stable structures. The combination of XPS measurements and modeling implies that the oxidation of polystyrene and Polyethylene is self-limiting on both hydrogen saturated and dehydrogenated (after argon ion plasma bombardment) surfaces.

Bharat I Chaudhary - One of the best experts on this subject based on the ideXlab platform.

  • 110th anniversary interactions of bis 1 methyl 1 phenylethyl peroxide with the secondary antioxidant bis octadecyloxycarbonylethyl sulfide mechanistic studies conducted in dodecane as a model system for Polyethylene
    Industrial & Engineering Chemistry Research, 2019
    Co-Authors: Sarath Chand Sarngadharan, Fiaz S Mohammed, Mark Conley, Harris Eldridge, Yusra Anwar, Derek Nursey, Jon Faris, Maryellen P Malone, Jeffrey M Cogen, Bharat I Chaudhary
    Abstract:

    Cross-linked Polyethylene (XLPE) is an important class of materials with critical applications  including pipes and high voltage electric cables. An organic peroxide such as bis(1-methyl-1-phenylethyl) peroxide (BMPEP) is a commonly used radical initiator in the cross-linking process along with a secondary antioxidant such as bis(octadecyloxycarbonylethyl) sulfide (BOCES). Herein is described a detailed investigation into the complex interactions of the radical initiator BMPEP and the secondary antioxidant BOCES in dodecane solvent–a model for the Polyethylene Polymer. Kinetic and spectroscopic experiments along with DFT calculations provide the foundation for a detailed mechanistic description for the roles of BMPEP, BOCES, atmospheric oxygen, and trace amounts of water in the overall process.

Kotiba Hamad - One of the best experts on this subject based on the ideXlab platform.

  • Melt Rheology of Poly(Lactic Acid)/Low Density Polyethylene Polymer Blends
    Advances in Chemical Engineering and Science, 2011
    Co-Authors: Kotiba Hamad, Mosab Kaseem, Fawaz Deri
    Abstract:

    In this work, rheological properties of poly (lactic acid) (PLA), low density Polyethylene (LDPE) Polymer blends were investigated in the molten state. The experiments were carried on a capillary rheometer. The effect of shear stress, temperature and blending ratio on the flow activation energy at a constant shear stress and melt viscosity of the blends are described. The results showed that the PLA/LDPE Polymer blends are pseudo plastic in nature, where there viscosity decreases with increasing shear stress. Also it was found the melt viscosity of the blends decreases with increasing PLA content in the blend