Linked Life Data

17143765

Source:http://linkedlifedata.com/resource/pubmed/id/17143765

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2006-12-4
pubmed:abstractText
Samples of untreated ultra-high molecular weight polyethylene (UHMW-PE), UHMW-PE sterilized with gamma-rays in nitrogen atmosphere (conventional UHMW-PE, widely used for articulating surfaces in endoprostheses) and UHMW-PE, which has been crosslinked by electron beam irradiation and annealed subsequently, were stabilized with alpha-tocopherol and aged in air at 120 degrees C as well as in 10% aqueous hydrogenperoxide with 0.04 mg/ml FeCl3 as catalyst at 50 degrees C. The oxidative degradation was monitored with the help of infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), solubility measurements and size exclusion chromatography (SEC) and were compared to unstabilized samples. When aged in air at 120 degrees C, the crosslinked UHMW-PE showed a slightly slower increase of the carbonyl (CO)-number (according to DIN 53383) in FTIR than conventional UHMW-PE. A stabilisation with 0.4% w/w alpha-tocopherol resulted in an increase of lifetime by a factor of approx. 40 for all samples. Ageing in 10% aqueous H2O2 at 50 degrees C yielded similar results for all three unstabilised samples. The addition of the natural antioxidant alpha-tocopherol led to a prolongation of lifetime by a factor of approx. 2.5. A linear loss of alpha-tocopherol was detected during ageing. An increase of crystallinity as well as lamella thickness during ageing was observed with the help of DSC. The two-phase structure of crosslinked UHMW-PE with two melting endotherms at 114 degrees C and 137 degrees C was replaced very quickly by a single melting point at 130 degrees C. This effect was delayed with the stabilized samples. In the solubility and SEC measurements, a severe molecular degradation and drop of molar mass of all materials could be observed after ageing in H2O2, leading to a complete destruction and, in case of crosslinked UHMW-PE, to a serious damage of the molecular network, respectively.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0957-4530
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1333-40
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Accelerated ageing experiments with crosslinked and conventional ultra-high molecular weight polyethylene (UHMW-PE) stabilised with alpha-tocopherol for total joint arthroplasty.
pubmed:affiliation
Department of Chemistry of Polymeric Materials, University of Leoben, 8700 Leoben, Austria. christian.wolf@unileoben.ac.at
pubmed:publicationType
Journal Article