Di-cumyl peroxide crosslinking of UHMWPE
AssigneeThe General Hospital Corporation
InventorsOrhun K. Muratoglu, Ebru Oral
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Abstract
The inventions provide methods of manufacturing peroxide cross-linked and high temperature melted polymeric material, for example ultra-high molecular weight polyethylene (UHMWPE) containing vitamin E, total joint implants with high wear resistance, high oxidation resistance, and very low concentration of residual by-products, as well as products made thereby.
Claims18
A peroxide cross-linked and high temperature melted polymeric material fabricated from peroxide crosslinked ultra-high molecular weight polyethylene containing vitamin-E, wherein ultra-high molecular weight polyethylene is first blended with di-cumyl peroxide and vitamin E to form a blend, wherein said blend is compression molded to obtain a crosslinked and consolidated article and cooled to about room temperature, wherein the crosslinked and consolidated article is then subjected to a high temperature melting (HTM) cycle in a reduced oxygen environment to produce a peroxide cross-linked and high temperature melted polymeric material, wherein the peroxide cross-linked and high temperature melted polymeric material has an acetophenone (ACP) index less than 0.03 and an elongation at break (EAB) less than 400%,
- wherein the high temperature melting cycle comprises
- heating the crosslinked and consolidated article above 250° C. for at least 50 hours and less than 70 hours, wherein during the heating the crosslinked and consolidated article is heated at 295±5° C. for a duration that is not longer than 9 hours.
A wear resistant medical implant fabricated from peroxide crosslinked ultra-high molecular weight polyethylene containing vitamin-E, wherein ultra-high molecular weight polyethylene is first blended with di-cumyl peroxide and vitamin E to form a blend, wherein the blend is compression molded to obtain a crosslinked and consolidated preform and cooled to about room temperature, wherein the crosslinked and consolidated preform is subjected to a high temperature melting (HTM) cycle in a reduced oxygen environment to produce a peroxide cross-linked and high temperature melted polymeric preform, wherein the peroxide cross-linked and high temperature melted polymeric preform has an acetophenone (ACP) index less than 0.03 and an elongation at break (EAB) less than 400%, wherein the peroxide cross-linked and high temperature melted polymeric preform is machined into a medical implant,
- wherein the high temperature melting cycle comprises heating the crosslinked and consolidated preform above 250° C. for at least 50 hours and less than 70 hours, wherein during the heating the crosslinked and consolidated preform is heated at 295±5° C. for a duration that is not longer than 9 hours.
Dependencies are inferred from the claim text.