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Characterization of commercial rigid polyurethane foams used as bone analogs for implant testing

Journal of Materials Science: Materials in Medicine volume 21, pages 1453–1461 (2010)Cite this article

Abstract

Mechanical properties and microstructure characterization of a series of graded commercial rigid polyurethane foams commonly used to mimic trabecular bone in testing orthopaedic devices is reported. Compressive testing conducted according to ASTM standard F1839-08, which requires large specimens (50.8 mm × 50.8 mm × 25.4 mm blocks) gave elastic modulus and compressive strength values ranging from 115 to 794 MPa and 4.7 to 24.7 MPa, respectively, for foams having densities of 0.240–0.641 g/cm3. All these results were within the requirements of the specification for the corresponding grades. Compression testing using smaller specimens (7.5 mm diameter × 15 mm) typical of testing bone, gave results in good agreement with those obtained in the standard tests. Microstructural measurements showed the average pore size ranged from 125 to 234 μm for densities ranging from 0.641 to 0.159 g/cm3, respectively. The relative modulus as a function of relative density of the foams fit well to the model of Gibson and Ashby. Cyclic testing revealed hysteresis in the lower density foams with a loading modulus statistically equivalent to that measured in monotonic testing. Shore DO durometry (hardness) measurements show good correlations to elastic modulus and compressive strength. The results suggest additional parameters to consider for the evaluation of polyurethane foams for bone analog applications.

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References

  1. Thompson MS, McCarthy ID, Lidgren L, Ryd L. Compressive and shear properties of commercially available polyurethane foams. J Biomech. 2003;125:732–4. doi:10.1115/1.1614820.

    Article  Google Scholar 

  2. Palissery V, Taylor M, Browne M. Fatigue characterization of a polymer foam to use as a cancellous bone analog material in the assessment of orthopaedic devices. J Mater Sci: Mater Med. 2004;15:61–7. doi:10.1023/B:JMSM.0000010098.65572.3b.

    Article  CAS  Google Scholar 

  3. American Society for Testing and Materials. ASTM F1839, standard specification for rigid polyurethane foam for use as a standard material for testing orthopaedic devices and instruments. West Conshohocken: ASTM; 2008. doi:10.1520/F1839-08.

    Google Scholar 

  4. Szivek JA, Thomas M, Benjamin JB. Characterization of a synthetic foam as a model for human cancellous bone. J Appl Biomater. 1993;4:269–72. doi:10.1002/jab.770040309.

    Article  CAS  PubMed  Google Scholar 

  5. Szivek JA, Thompson JD, Benjamin JB. Characterization of three formulations of a synthetic foam as models for a range of human cancellous bone types. J Appl Biomater. 1995;6:125–8. doi:10.1002/jab.770060207.

    Article  CAS  PubMed  Google Scholar 

  6. Hein TJ, Hotchkiss R, Perissinotto A, Chao EYS. Analysis of bone model material for external fracture fixation experiments. Biomed Sci Instrum. 1987;22:43–8.

    Google Scholar 

  7. Gibson LJ, Ashby MF. Cellular solids. 2nd ed. Cambridge: Cambridge University Press; 1999.

    Google Scholar 

  8. Patel MF, Finnie I. Structural features and mechanical properties of rigid cellular plastics. J Mater. 1970;5:909–32.

    Article  CAS  Google Scholar 

  9. Rehkopf JD, McNeice GM, Brodland GW. Fluid and matrix components of polyurethane foam behavior under cyclic compression. J Eng Mater Technol. 1996;118:58–62. doi:10.1007/BF02328691.

    Article  CAS  Google Scholar 

  10. Shen Y, Golnaraghi F, Plumtree A. Modeling compressive cyclic stress-strain behaviour of structural foam. Int J Fatigue. 2001;23:491–7. doi:10.1016/S0142-1123(01)00014-7.

    Article  CAS  Google Scholar 

  11. American Society for Testing and Materials. ASTM F1839, standard specification for rigid polyurethane foam for use as a standard material for testing orthopaedic devices and instruments. West Conshohocken: ASTM; 1997. doi:10.1520/F1839-97.

    Google Scholar 

  12. American Society for Testing and Materials. ASTM F1839, standard specification for rigid polyurethane foam for use as a standard material for testing orthopaedic devices and instruments. West Conshohocken: ASTM; 2001. doi:10.1520/F1839-01.

    Google Scholar 

  13. American Society for Testing and Materials. ASTM D1621 standard test method for compressive properties of rigid cellular plastics. West Conshohocken: ASTM; 2004. doi:10.1520/D1621-04A.

    Google Scholar 

  14. Underwood EE. Quantitative stereology. Reading: Addison-Wesley; 1970.

    Google Scholar 

  15. Røhl L, Larsen E, Linde F, Odgaard A, Jørgensen J. Tensile and compressive properties of cancellous bone. J Biomech. 1991;24:1143–9. doi:10.1016/0021-9290(91)90006-9.

    Article  PubMed  Google Scholar 

  16. Williams JL, Lewis JL. Properties and an anisotropic model of cancellous bone from the procimal tibial epiphysis. J Biomech Eng. 1982;104:50–6.

    Article  CAS  PubMed  Google Scholar 

  17. Rice JC, Cowin SC, Bowman JA. On the dependence of the elasticity and strength of cancellous bone on apparent density. J Biomech. 1988;21:155–68.

    Article  CAS  PubMed  Google Scholar 

  18. American Society for Testing and Materials. ASTM D2240-05, standard test method for rubber property-durometer hardness. West Conshohocken: ASTM; 2005. doi:10.1520/D2240-05.

    Google Scholar 

  19. Lee ST, Ramesh NS, editors. Polymeric foams: mechanisms and materials. Boca Raton: CRC Press; 2004.

    Google Scholar 

  20. Gibson LJ, Ashby MF. The mechanics of three-dimensional cellular materials. Proc R Soc Lond A. 1982;382:43–59. doi:10.1098/rspa.1982.0088.

    Article  CAS  ADS  Google Scholar 

  21. Roff WJ, Scott JR. Fibers, films, plastics and rubbers: a handbook of common polymers. London: Butterworths; 1971.

    Google Scholar 

  22. General Plastics. Interactive datasheets. 2009. http://www.generalplastics.com/products/idatasheets.php. Accessed 15 June 2009.

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Acknowledgments

Support for this research by Zimmer, Inc., Warsaw, IN, is gratefully acknowledged.

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Affiliations

  1. School of Materials Engineering, Purdue University, West Lafayette, IN, USA

    Kayla L. Calvert & Kevin P. Trumble

  2. Division of Engineering, Brown University, Providence, RI, USA

    Thomas J. Webster

  3. Zimmer, Inc, Warsaw, IN, USA

    Lynn A. Kirkpatrick

Authors
  1. Kayla L. Calvert
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  2. Kevin P. Trumble
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  3. Thomas J. Webster
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  4. Lynn A. Kirkpatrick
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Correspondence to Kayla L. Calvert.

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Calvert, K.L., Trumble, K.P., Webster, T.J. et al. Characterization of commercial rigid polyurethane foams used as bone analogs for implant testing. J Mater Sci: Mater Med 21, 1453–1461 (2010). https://doi.org/10.1007/s10856-010-4024-6

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  • DOI: https://doi.org/10.1007/s10856-010-4024-6

Keywords

  • Foam
  • Compressive Strength
  • True Density
  • Average Cell Size
  • General Plastic