scholarly journals Wear-Resistant Ultrahigh-Molecular-Weight Polyethylene-Based Nano- and Microcomposites for Implants

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
S. V. Panin ◽  
L. A. Kornienko ◽  
N. Sonjaitham ◽  
M. V. Tchaikina ◽  
V. P. Sergeev ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Wear Resistance ◽  
Surface Treatment ◽  
Bulk Material ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
High Energy ◽  
Hydroxyapatite Nanoparticles ◽  
Scanning Calorimetry ◽  
Tribotechnical Properties ◽  
Ultrahigh Molecular Weight

The influence of modification by hydroxyapatite (HA) nano- and microparticles on tribotechnical properties of ultrahigh-molecular-weight polyethylene (UHMWPE) was investigated to develop polymer implants for endoprosthesis. It was shown that modification of UHMWPE by hydroxyapatite nanoparticles within range of 0.1–0.5 wt.% results in increase of wear resistance at dry sliding by 3 times. On the other hand adding of 20 wt.% of micron size HA gives rise to the same effect. The effect of increasing wear resistance is not substantially changed at surface treatment of the nano- and microcomposites by N+ion beams as compared with nonirradiated blends. Preliminary joint mechanical activation of UHMWPE powder and fillers results in more uniform distribution of nanofillers in the matrix and, as a result, formation of more ordered structure. Structure within bulk material and surface layers was studied by means of optical profilometry, scanning electron microscopy, infrared spectroscopy, and differential scanning calorimetry. It is shown that adding of hydroxyapatite nanoparticles and high-energy surface treatment of the composite by N+ion implantation improve tribotechnical properties of UHMWPE due to formation of chemical bonds in the composite (crosslinking) and ordering of permolecular structure.

Tribological properties of ultrahigh-molecular-weight polyethylene (UHMWPE) composites reinforced with different contents of glass and carbon fibers

2019 ◽  
Vol 71 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Yanzhen Wang ◽  
Zhongwei Yin
Keyword(s):  
Molecular Weight ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
High Performance ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Content Type ◽  
Ultrahigh Molecular Weight ◽  
Pin On Disc ◽  
Uhmwpe Composites ◽  
Uhmwpe Composite

PurposeThis purpose of this study was to investigate the effects of carbon fiber (CF) and/or glass fiber (GF) fillers on the tribological behaviors of ultrahigh-molecular-weight polyethylene (UHMWPE) composites to develop a high-performance water-lubricated journal bearing material.Design/methodology/approachTribological tests were conducted using a pin-on-disc tribometer using polished GCr15 steel pins against the UHMWPE composite discs under dry conditions with a contact pressure of 15 MPa and a sliding speed of 0.15 m/s. Scanning electron microscopy, laser 3D micro-imaging profile measurements and energy-dispersive X-ray spectrometry were used to analyze the morphologies and elemental distributions of the worn surfaces.FindingsThe results showed that hybrid CF and GF fillers effectively improved the wear resistance of the composites. The fiber fillers decreased the contact area, promoted transfer from the polymers and decreased the interlocking and plowing of material pairs, which contributed to the reduction of both the friction coefficient and the wear rate.Originality/valueThe UHMWPE composite containing 12.5 Wt.% CF and 12.5 Wt.% GF showed the best wear resistance of 2.61 × 10−5mm3/(N·m) and the lower friction coefficient of 0.12 under heavy loading. In addition, the fillers changed the worn surface morphology and the wear mechanism of the composites.

scholarly journals Porous Ultrahigh Molecular Weight Polyethylene/Functionalized Activated Nanocarbon Composites with Improved Biocompatibility

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6065
Author(s):  
Wangxi Fan ◽  
Xiuqin Fu ◽  
Zefang Li ◽  
Junfei Ou ◽  
Zhou Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Contact Angle ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Biomedical Applications ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
In Vitro Experiments ◽  
Ultrahigh Molecular Weight ◽  
Uhmwpe Composite

Ultrahigh molecular weight polyethylene (UHMWPE) materials have been prevalent joint replacement materials for more than 45 years because of their excellent biocompatibility and wear resistance. In this study, functionalized activated nanocarbon (FANC) was prepared by grafting maleic anhydride polyethylene onto acid-treated activated nanocarbon. A novel porous UHMWPE composite was prepared by incorporating the appropriate amount of FANC and pore-forming agents during the hot-pressing process for medical UHMWPE powder. The experimental results showed that the best prepared porous UHMWPE/FANC exhibited appropriate tensile strength, porosity, and excellent hydrophilicity, with a contact angle of 65.9°. In vitro experiments showed that the porous UHMWPE/FANC had excellent biocompatibility, which is due to its porous structure and hydrophilicity caused by FANC. This study demonstrates the potential viability for our porous UHMWPE/FANC to be used as cartilage replacement material for biomedical applications.

Study of hydrogen annealing of ultrahigh molecular weight polyethylene irradiated with high-energy protons

1999 ◽  
Vol 14 (11) ◽  
pp. 4431-4436 ◽  
Author(s):  
J. F. Wilson ◽  
J. R. Liu ◽  
F. Romero-Borja ◽  
Wei-Kan Chu
Keyword(s):  
Molecular Weight ◽  
Free Radicals ◽  
Proton Irradiation ◽  
Ion Irradiation ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Orthopedic Implants ◽  
High Energy ◽  
Hydrogen Annealing ◽  
Ultrahigh Molecular Weight ◽  
End Groups

Ultrahigh molecular weight polyethylene, an important biomaterial for orthopedic implants, was irradiated with 2.6- and 3-MeV H+ ions at low doses from 5.7 × 1011 to 2.3 × 1014 ions/cm2. Fourier transform infrared spectroscopy showed that irradiation resulted in increased free radicals, carbon double bonds, and increased methyl and vinyl end groups. The free radicals resulted in poor polymer oxidative stability, as measured by increased carbonyl concentration. Hydrogen annealing after ion irradiation reacted with the free radicals generated during proton irradiation resulted in a 40–50% decrease in infrared absorption associated with carbonyl and prevented further oxidation.

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