Nanomechanical properties of self-reinforced composite poly(methyl methacrylate) as a function of processing temperature.

Understanding the wear characteristics of bone cement and its alternatives is critical to improving the quality and longevity of hip replacements. A novel composite material, self-reinforced composite poly(methyl methacrylate), has been previously developed for potential use as a pre-coat material for hip implants. The goal of this work was to examine the properties of self-reinforced composite poly(methyl methacrylate) as a function of processing temperature. Nanoindentation tests were performed to measure hardness and modulus of self-reinforced composite poly(methyl methacrylate) at the nanoscale. Nanoscratch tests were performed parallel, orthogonal, and longitudinal to composite fibers to measure residual scratch depths. Significant differences were found in the hardness, modulus, and residual scratch depth as a function of processing temperature when compared to poly(methyl methacrylate). As processing temperature is increased, hardness decreased and residual scratch depths increased. Data also showed that fiber orientation plays a critical role in scratch resistance. Scratching orthogonal to fiber orientation produced the least residual scratch depth ranging from 524 nm at 105 degrees C to 838 nm at 150 degrees C, compared to a residual scratch depth for poly(methyl methacrylate) of 842 nm. Copyright (c) 2005 Wiley Periodicals, Inc.