Synergistic effects of blending multiple additives in UHMWPE

摘要

Oxidation resistant crosslinked ultrahigh molecular weight polyethylene (UHMWPE) is described, wherein at least two different additives in the manufacture synergistically increase the oxidation resistance of crosslinked UHMWPE. This allows the manufacture of oxidation resistant crosslinked UHMWPE using lower levels of additives and/or lower levels of crosslinking irradiation or chemicals. The lower levels of additives and/or crosslinking produce crosslinked UHMWPE having desired physical properties not possible without the synergistic interaction of the additives. This crosslinked UHMWPE may be used in medical prostheses such as in bearing components having desired physical properties such as wear resistance and oxidation resistance not possible without the synergistic interaction of the additives.

主权项

1. A process for preparing crosslinked oxidation resistant UHMWPE for use in medical prostheses comprising the steps of: (i) obtaining UHMWPE resin; (ii) crosslinking the UHMWPE, (iii) combining the UHMWPE resin with both a first amount of a first additive and a second amount of a second additive, wherein the first and the second additives are different additives; (iv) consolidating the crosslinked UHMWPE that has been combined with the first and second additives to create oxidation resistant UHMWPE, wherein the first and second additives synergistically increase the oxidation resistance of the crosslinked UHMWPE, and wherein the amount of the first additive that is combined with the UHMWPE in step (iii) is about 50 ppm to about 2,000 ppm, and wherein the amount of the second additive that is combined with the UHMWPE in step (iii) is about 50 ppm to about 2,000 ppm.