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Degradation Mechanism and Effects of Vitamin E addition in UHMWPE Hip Implants

Luisetto, Yannick LU (2003)
Abstract
Wear of the UHMWPE component is one of the major concerns in joint replacement surgery, triggering prosthetic loosening leading to revision. The understanding of the mechanisms of material degradation, especially in regard to oxidation, is one of the keys to significantly improve the mechanical properties. This work focused on the relationship between the failure mechanism, crosslinking and oxidation of the material. The effects of gamma-irradiation and annealing were investigated. ƒ×-Irradiation and aging cause oxidation of the material, and annealing at high temperature can significantly reduce this oxidation. Oxidation leads to a decrease in mechanical properties and wear resistance. This work also investigated the effect of the... (More)
Wear of the UHMWPE component is one of the major concerns in joint replacement surgery, triggering prosthetic loosening leading to revision. The understanding of the mechanisms of material degradation, especially in regard to oxidation, is one of the keys to significantly improve the mechanical properties. This work focused on the relationship between the failure mechanism, crosslinking and oxidation of the material. The effects of gamma-irradiation and annealing were investigated. ƒ×-Irradiation and aging cause oxidation of the material, and annealing at high temperature can significantly reduce this oxidation. Oxidation leads to a decrease in mechanical properties and wear resistance. This work also investigated the effect of the addition of an antioxidant, Vitamin E (VE) to the material. VE improves the oxidation resistance of irradiated UHMWPE but has also some impact on the mechanical properties, wear and oxidation of irradiated UHMWPE. Irradiation in presence of VE leads to an inhomogeneous material, a decrease in crosslink density and molecular weight. The morphology of the resulting material is consistent with a composite-like morphology where highly crosslinked domains are imbedded in a less crosslinked matrix. It was found that the mechanical properties of irradiated VE-containing materials depend on the VE concentration and appeared to be optimal for 0.2 w%VE. Volumetric wear is directly related to crosslink density. On the other hand, the coefficient of friction is related to the mechanical properties of the material, but not directly to the crosslink density. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Professor Ambrosio, Luigi, Italy
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Polymer technology, Polymerteknik, biopolymers
pages
111 pages
publisher
Polymer Science & Engineering Center for Chemistry and Chemical Engineering Lund University
defense location
Lecture Hall F, Center for Chemistry and Chemical Engineering, Lund Institute of Technology
defense date
2003-06-10 10:15
ISBN
91-7422-024-1
language
English
LU publication?
yes
id
b845682a-e1b4-473b-9649-e135b611b58f (old id 465960)
date added to LUP
2007-10-14 14:15:29
date last changed
2016-09-19 08:45:03
@phdthesis{b845682a-e1b4-473b-9649-e135b611b58f,
  abstract     = {Wear of the UHMWPE component is one of the major concerns in joint replacement surgery, triggering prosthetic loosening leading to revision. The understanding of the mechanisms of material degradation, especially in regard to oxidation, is one of the keys to significantly improve the mechanical properties. This work focused on the relationship between the failure mechanism, crosslinking and oxidation of the material. The effects of gamma-irradiation and annealing were investigated. ƒ×-Irradiation and aging cause oxidation of the material, and annealing at high temperature can significantly reduce this oxidation. Oxidation leads to a decrease in mechanical properties and wear resistance. This work also investigated the effect of the addition of an antioxidant, Vitamin E (VE) to the material. VE improves the oxidation resistance of irradiated UHMWPE but has also some impact on the mechanical properties, wear and oxidation of irradiated UHMWPE. Irradiation in presence of VE leads to an inhomogeneous material, a decrease in crosslink density and molecular weight. The morphology of the resulting material is consistent with a composite-like morphology where highly crosslinked domains are imbedded in a less crosslinked matrix. It was found that the mechanical properties of irradiated VE-containing materials depend on the VE concentration and appeared to be optimal for 0.2 w%VE. Volumetric wear is directly related to crosslink density. On the other hand, the coefficient of friction is related to the mechanical properties of the material, but not directly to the crosslink density.},
  author       = {Luisetto, Yannick},
  isbn         = {91-7422-024-1},
  keyword      = {Polymer technology,Polymerteknik,biopolymers},
  language     = {eng},
  pages        = {111},
  publisher    = {Polymer Science & Engineering Center for Chemistry and Chemical Engineering Lund University},
  school       = {Lund University},
  title        = {Degradation Mechanism and Effects of Vitamin E addition in UHMWPE Hip Implants},
  year         = {2003},
}