Hot compaction of poly(methyl methacrylate) composites based on fiber shrinkage results
- 149 Downloads
Uniaxial self-reinforced composite poly(methyl methacrylate) (SRC-PMMA) is being investigated as a pre-coat material for the femoral component of total hip replacements. Hot compaction of self-reinforced composites is largely an empirical process which varies the processing parameters of time, temperature and pressure until the desired properties are obtained. Previous work has shown that PMMA fibers have unique thermal relaxation properties dependent upon the retained molecular orientation in them. This work processed composites at times and temperatures that span the relaxation process for a single fiber. It was found that molecular orientation, as measured by birefringence, was lost in composites processed at times greater than relaxation times for single fibers. Flexural properties were also found to vary with processing conditions, with the highest values of 165 ± 15 MPa and 168 ± 3 MPa found at high and low processing times, respectively. These are significantly stronger than unreinforced PMMA which has a flexural strength of 127 ± 14 MPa. It is hypothesized that diffusion between fibers occurs much more quickly than the loss of molecular orientation and it was seen that SRC-PMMA processing conditions can be predicted from the relaxation times and temperatures from single fibers.
KeywordsPMMA Flexural Strength Femoral Component Methyl Methacrylate Single Fiber
Unable to display preview. Download preview PDF.
- 1.M. J. BONNER, P. J. HINE and I. M. WARD, Plast., Rubb. Comp. Process. Techn. 27 (1998) 58.Google Scholar
- 8.I. M. WARD, Plast., Rubb. and Comp. Process. Appl. 19 (1993) 7.Google Scholar
- 9.D. W. WOODS and I. M. WARD, Polymer 29 (1994) 2572.Google Scholar
- 22.A. MAJOLA, S. VAINIONPÅå, K. VIHTONEN, M. MERO, J. VASENIUS, P. TÖRMåLå and P. ROKKANEN, Clin. Orthop. Rel. Res. 268 (1991) 260.Google Scholar
- 26.H. H. PELTONIEMI, R. M. TULAMO, T. TOIVONEN, D. HALLIKAINEN, P. TÖRMåLå and T. WARIS, J. Neurosur. 90 (1999) 910.Google Scholar
- 38.J. L. GILBERT, D. S. NEY and E. P. LAUTENSCHLAGER, Biomater (1995) 1043.Google Scholar
- 40.W. J. PEERS, D. D. WRIGHT and I. MISKIOGLU, Wear (submitted July 2003) .Google Scholar
- 44.Standard test methods for flexural properties of unreinforced and reinforced plastics and electrical insulating materials [Metric], ASTM Specification D790M-86, ASTM Standards (ASTM, Philadelphia, PA, USA, 1990).Google Scholar
- 46.L. H. SPERLING, “Introduction to Physical Polymer Science” (John Wiley and Sons, Inc., New York, 1992).Google Scholar