Crosslinked polymers including one or more antioxidants, methods for making same and methods for selecting antioxidants

摘要

The present disclosure is directed to polymer compositions having one or more antioxidants providing high crosslink density and improved oxidation resistance to the polymer composition and methods for making same. Such polymer compositions can be advantageously used to make orthopedic implants. The disclosure also provides methods for selecting antioxidants providing desirable properties to the polymer composition. In one embodiment, a measure of OIT can be used to select the antioxidant and antioxidant blend. In another embodiment, measurements of OIT and OI-rate can be used to select the one or more antioxidants. In an other embodiment, the product of OIT and crosslink density can be calculated to predict wear resistance and oxidation resistance of a polymer composition including one or more antioxidants.

主权项

1. An orthopedic implant comprising:
a homogeneous consolidated and crosslinked UHMWPE blend comprising UHMWPE resin,
a first antioxidant that is a primary antioxidant chosen from lauryl gallate, octyl gallate, propyl gallate, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, vitamin E, gamma-tocopherol, 2,2,5,7,8-penta-methyl-6-chromanol, and gallic acid, anda second antioxidant that is bis(2,4-dicumylphenyl)pentaerythritol diphosphite; wherein a combined concentration of the first and second antioxidants prior to crosslinking is about 0.05% to about 5% by weight of the UHMWPE blend.