Characterization and degradation of polymer composites for orthopaedic applications.

摘要

The purpose of this work was to examine the interaction between the physiological environment and polymer composite materials intended for use in orthopaedic applications. This was accomplished through three primary objectives. The first objective was to evaluate the use of small-scale flexural test specimens for composite material characterization. Miniflexbars were cut from injection-molded CFRPEEK bendbars. Variation in flexural properties of these MFBs were shown to correlate with variations in local microstructure within the intact bendbar. An overall decrease in flexural strength was found for the MFBs when compared with the flexural strength of the intact bendbar. This could be explained by microstructural differences in fiber orientation and distribution.;The second objective of this work was to use the characterized specimens in exposure studies to test polymer composites in simulated in vivo environments. MFBs were used to examine the effects of serum on flexural properties of various composites. Injection-molded CFRPEEK MFBs, continuous fiber reinforced PEEK MFBs, and injection molded CFRPSU MFBs were exposed to 10% serum for 36 weeks at 37;Lastly, in conjunction with evaluation of composite degradation due to exposure to serum in vitro using MFBs, degradation products recovered from composite wear in vivo and in vitro were also evaluated. First, a digestion protocol using concentrated HNO