抄録
In joint prostheses where ultra-high molecular weight polyethylene (UHMWPE) is used as bearing material, efficacious treatments such as crosslinking, addition of vitamin E and the grafting of phospholipid polymer are known to have improved wear resistance. However, friction and wear problems have not yet been completely solved under severe conditions, where direct contacts can occur in mixed or boundary lubrication. Accordingly, joint prostheses containing artificial hydrogel cartilage with properties similar to those of articular cartilage are expected to show superior tribological functions. The application of poly(vinyl alcohol) (PVA) hydrogel with high water content as biomimetic compliant artificial cartilage is expected to reproduce similar adaptive multimode lubrication mechanism to natural synovial joints. In this paper, the tribological behaviors of three kinds of PVA hydrogels different in preparation methods were evaluated was evaluated in reciprocating tests lubricated with saline and simulated synovial fluid. The interstitial fluid pressure and friction for PVA hydrogels were estimated by biphasic finite element analysis. The superior lubricating performance of PVA hybrid gel was discussed from biphasic and boundary lubrication.
