Reinforcing Effect of Organo-modified Layered Silicates in High-Density Polyethylene

2005 ◽  
Vol 5 (6) ◽  
pp. 958-963 ◽  
Author(s):  
M. Modesti ◽  
S. Besco ◽  
A. Lorenzetti ◽  
G. Zanirato ◽  
F. Rauli
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Layered Silicates ◽  
Reinforcing Effect

Investigation of the Relaxation Mechanical Properties of Nanocomposites Based on High-Density Polyethylene

2018 ◽  
Vol 45 (3) ◽  
pp. 91-96
Author(s):  
N.S. Dikanova ◽  
A.V. Matseevich ◽  
O.V. Kovriga ◽  
A.A. Askadskii ◽  
T.P. Kravchenko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stress Relaxation ◽  
Specific Surface ◽  
Relaxation Process ◽  
High Density Polyethylene ◽  
High Density ◽  
Entire Period ◽  
Reinforcing Effect ◽  
Low Concentration ◽  
Multiwall Nanotubes

The effect of nanotubes and nanofibres on the stress relaxation of nanocomposites based on high-density polyethylene (HDPE) was studied. It was found that a very low concentration of multiwall nanotubes (0.1 wt%) leads to a significant increase in the relaxing stresses over the entire period of relaxation. Generalised curves of the relaxation process were plotted, and it was found that the greatest reinforcing effect is rendered by the multiwall nanotubes with the greatest specific surface.

Composition and Surface Topography Effects on Apatite-Forming Ability of Ceramic-Polymer Composites

2003 ◽  
Vol 774 ◽  
Author(s):  
Susan M. Rea ◽  
Serena M. Best ◽  
William Bonfield
Keyword(s):  
Surface Topography ◽  
High Density Polyethylene ◽  
High Density ◽  
Apatite Layer ◽  
Biologically Active ◽  
Human Blood Plasma ◽  
Apatite Formation ◽  
Polyethylene Matrix ◽  
Composite Surface ◽  
X Ray

AbstractHAPEXTM (40 vol% hydroxyapatite in a high-density polyethylene matrix) and AWPEX (40 vol% apatite-wollastonite glass ceramic in a high density polyethylene matrix) are composites designed to provide bioactivity and to match the mechanical properties of human cortical bone. HAPEXTM has had clinical success in middle ear and orbital implants, and there is great potential for further orthopaedic applications of these materials. However, more detailed in vitro investigations must be performed to better understand the biological interactions of the composites and so the bioactivity of each material was assessed in this study. Specifically, the effects of controlled surface topography and ceramic filler composition on apatite layer formation in acellular simulated body fluid (SBF) with ion concentration similar to those of human blood plasma were examined. Samples were prepared as 1 cm × 1 cm × 1 mm tiles with polished, roughened, or parallel-grooved surface finishes, and were incubated in 20 ml of SBF at 36.5 °C for 1, 3, 7, or 14 days. The formation of a biologically active apatite layer on the composite surface after immersion was demonstrated by thin-film x-ray diffraction (TF-XRD), environmental scanning electron microscopy (ESEM) imaging and energy dispersive x-ray (EDX) analysis. Variations in sample weight and solution pH over the period of incubation were also recorded. Significant differences were found between the two materials tested, with greater bioactivity in AWPEX than HAPEXTM overall. Results also indicate that within each material the surface topography is highly important, with rougher samples correlated to earlier apatite formation.

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