Standard Practice for Lipid Preconditioning of Ultra-High-Molecular-Weight Polyethylene for Accelerated Aging

Importancia y uso:

4.1 This practice summarizes two methods that may be used to precondition UHMWPE by the absorption of lipids to differentiate the simulated in vitro oxidative stability of UHMWPEs, after lipid exposure.

4.1.1 Procedure A, High Squalene Absorption—This method of preconditioning with lipids may be used for comparative oxidative stability testing to screen different materials under aggressive conditions.

4.1.2 Procedure B, Mixed Lipid Absorption—This method of preconditioning may be used for comparative oxidative stability testing under mild conditions that more closely simulate in-vivo conditions.

4.2 This practice may be used to accelerate the oxidation of UHMWPE components when using elevated temperature and elevated oxygen pressure according to the methods of Practice F2003. Under real-time conditions such as implantation, oxidative changes to UHMWPE formulations may take months or years to produce changes that may result in deleterious mechanical performance. The method outlined in this practice permits the preparation of UHMWPE for evaluation of oxidative stability in a relatively short period of time (for example, weeks).

4.3 This practice may also be used to precondition UHMWPE test specimens prior to characterization of their physical and chemical properties. In particular, this practice may be used for preconditioning with lipids prior to oxidation induction time (OIT) testing as outlined in Test Method D3895.

Subcomité:

F04.15

Volúmen:

13.02

Número ICS:

83.080.20 (Thermoplastic materials)

Palabras clave:

aging; oxidation; preconditioning; stability; UHMWPE; ultra-high molecular weight polyethylene;