Results 131 to 140 of about 3,612 (181)

Catalysts for UHMWPE and UHMWPE-copolymers

Inorganica Chimica Acta, 2010
Abstract Classic inorganic and more recent organometallic compounds capable of polymerizing ethylene to ultra high molecular are compared. Activated catalysts showed varying degrees of productivity when challenged with co-monomers. The general activity trend followed TiCl 3 3 N -(3,5-diiodosalicylidene)cycloheptylamine titanium dichloride was ...
Robert L. Jones, Mahmoud Z. Armoush, Tjhunina Harjati, Michael Elder, Albert A. Hummel, Jeffrey Sullivan   +5 more
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Oxidation of orthopaedic UHMWPE

Biomaterials, 2002
Retrieved EtO sterilised acetabular cups usually show much less degradation than gamma-ray sterilised cups. Some of our retrieved EtO sterilised cups did, however, reveal unexpected bulk oxidation. It was observed that this oxidation was always accompanied by whitening of the material. This whitening was found to be due to a break-up of the compression
L, Costa, K, Jacobson, P, Bracco, E M, Brach del Prever   +3 more
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Catalysts for UHMWPE

Macromolecular Symposia, 2009
AbstractPolyolefin coordination catalysts useful for producing UHMWPE are surveyed, including classic Ziegler‐Natta (ZN), current commercial generation ZN, metallocene single site, and non‐metallocene. Catalysts were prepared and compared for productivity and selected polymer properties under a variety of conditions.
R.L. Jones, M. Armoush
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Accelerated aging studies of UHMWPE. II. Virgin UHMWPE is not immune to oxidative degradation

Journal of Biomedical Materials Research, 2002
AbstractIn Part I of this series, we showed that aging at elevated oxygen pressure is more successful at increasing the depth to which degradation occurs although it, too, generally causes greater degradation at the surface than at the subsurface.
A A, Edidin, M L, Villarraga, M P, Herr, J, Muth, S S, Yau, S M, Kurtz   +5 more
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Mechanical and tribological properties of short discontinuous UHMWPE fiber reinforced UHMWPE

Polymer Bulletin, 1997
The tribological properties of Ultra-High Molecular Weight Polyethylene have generated new concern regarding the long-term clinical performance of total joint replacements. To extend the lifetime of artificial joints, it is necessary to decrease the wear rate of UHMWPE. One possible solution is the incorporation of UHMWPE fibers.
Hofste, JM, vanVoorn, B, Pennings, AJ
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Thermal degradation of UHMWPE

Journal of Thermal Analysis, 1997
The thermal behaviour of ultra-high molecular weight polyethylene (UHMWPE) of different molecular weights was examined by thermal analysis methods. The melting temperatureTm and the heat of melting δH were measured by the DSC method. The thermooxidative degradation process was investigated by using a MOM Q-1500 D derivatograph at various heating rates ...
E. Rudnik, Z. Dobkowski
openaire   +1 more source

Processing of UHMWPE and HA/UHMWPE nanocomposite for biomedical applications

2014
Ultrahigh molecular weight polyethylene (UHMWPE) is an implant material for orthopedic implants because of its excellent mechanical properties. However, its applications were limited by the poor processability, particularly its use as matrix materials for bone-analogue.
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Wear of the UHMWPE Cup

2016
Removal or transfer of material from contacting surfaces due to their relative movement under load. Wear can be measured by mass change, volume measurement or by the depth of the wear tracks. The two inevitable consequences are shedding of wear products and change of the geometry of the articulation.
B. M. Wroblewski, Paul D. Siney, Patricia A. Fleming   +2 more
openaire   +1 more source

In vivo UHMWPE biodegradation of retrieved prosthesis

Biomaterials, 1998
Sixty-two ultra high molecular weight polyethylene prosthetic components (PEs) (31 tibial plateaux and 31 cups), sterilised by gamma rays or ethylene oxide (EtO), were retrieved after 1-12 years depending on different medical reasons and were studied by FTIR spectroscopy with derivatisation of oxidised species.
L, Costa, M P, Luda, L, Trossarelli, E M, Brach del Prever, M, Crova, P, Gallinaro   +5 more
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Dispersion of Pristine Cnt in Uhmwpe Solution to Prepare Cnt/Uhmwpe Composite Fiber

Polymers and Polymer Composites, 2014
CNT dispersion in polymer matrices uniformly remains a challenge. Uniform dispersion of carbon nanotube (CNT) within ultra-high molecular polyethylene (UHMWPE) solution is the first step to achieve CNT/UHMWPE fibers with excellent properties. Several approaches have been tried.
Xiangyang Hao, An-Ting Chien, Xiaoying Hua, Jian Lu, Yaodong Liu   +4 more
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