Highly crystalline cross-linked oxidation-resistant polyethylene
AssigneeThe General Hospital Corporation
InventorsOrhun K. Muratoglu, Ebru Oral
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Abstract
The present invention relates to methods for making highly crystalline cross-linked polymeric material, for example, highly crystalline cross-linked ultra-high molecular weight polyethylene (UHMWPE). The invention also provides methods of making antioxidant-doped highly crystalline cross-linked polymeric material using high pressure and high temperature crystallization processes, medical implants made thereof, and materials used therein.
Claims30
A medical implant comprising an oxidation resistant, cross-linked polymeric blend made by a process comprising the steps of:
- a) mixing a polymeric material with an antioxidant to form a polymeric blend, wherein the mixing is in the absence of a supercritical fluid, and wherein the polymeric material is polymeric resin powder, polymeric flakes, polymeric particles, or a mixture thereof;
- b) consolidating the polymeric blend;
- c) irradiating the polymeric blend by ionizing radiation at an elevated temperature that is above room temperature and below the peak melting point of the polymeric blend, thereby forming a cross-linked polymeric blend;
- d) mechanically deforming the cross-linked polymeric blend at a temperature below its melting point, thereby forming a mechanically deformed cross-linked polymeric blend;
- e) annealing the mechanically deformed cross-linked polymeric blend, thereby forming an oxidation resistant cross-linked polymeric blend;
- and
- f) machining the oxidation resistant cross-linked polymeric blend, thereby forming the medical implant.
A method of making a medical implant comprising an oxidation resistant cross-linked blend of polymeric material, wherein the oxidation resistant cross-linked blend of polymeric material is made by a process comprising the steps of:
- a) blending the polymeric material with an antioxidant, wherein the blending is in the absence of a supercritical fluid, and wherein the polymeric material is polymeric resin powder, polymeric flakes, polymeric particles, or a mixture thereof;
- b) consolidating the blend;
- c) irradiating the blend of polymeric material with ionizing radiation at an elevated temperature that is above room temperature and below the melting point of the blend of polymeric material, thereby forming a cross-linked blend of polymeric material;
- and
- d) machining the cross-linked blend of polymeric material, thereby forming the medical implant.
A method of making a medical implant comprising an oxidation resistant cross-linked and interlocked hybrid material, wherein the oxidation resistant cross-linked and interlocked hybrid material is made by a process comprising the steps of:
- a) blending the polymeric material with an antioxidant, thereby forming a polymeric blend, wherein the blending is in the absence of a supercritical fluid, and wherein the polymeric material is polymeric resin powder, polymeric flakes, polymeric particles, or a mixture thereof;
- b) compression molding the polymeric blend to the counterface of a second material, thereby forming an interlocked hybrid material having an interface between the polymeric blend and the second material;
- c) irradiating the interlocked hybrid material with ionizing radiation at an elevated temperature that is above room temperature and below the melting point of the polymeric blend, thereby forming a cross-linked and interlocked hybrid material;
- and
- d) machining the cross-linked interlocked hybrid material, thereby forming the medical implant.
Dependencies are inferred from the claim text.