University of Wyoming, Department of Mechanical Engineering, Laramie, WY 82071, USA.
University of Colorado Denver, Department of Mechanical Engineering, Denver, CO, USA.
J Mech Behav Biomed Mater. 2014 Feb;30:347-57. doi: 10.1016/j.jmbbm.2013.10.012. Epub 2013 Oct 25.
The focus of this study was to fabricate and investigate the mechanical behavior of porous poly(para-phenylene) (PPP) for potential use as a load-bearing orthopedic biomaterial. PPPs are known to have exceptional mechanical properties due to their aromatic backbone; however, the manufacturing and properties of PPP porous structures have not been previously investigated. Tailored porous structures with either small (150-250µm) or large (420-500µm) pore sizes were manufactured using a powder-sintering/salt-leaching technique. Porosities were systematically varied using 50 to 90vol%. Micro-computed tomography (µCT) and scanning electron microscopy (SEM) were used to verify an open-cell structure and investigate pore morphology of the scaffolds. Uniaxial mechanical behavior of solid and porous PPP samples was characterized through tensile and compressive testing. Both modulus and strength decreased with increasing porosity and matched well with foam theory. Porous scaffolds showed a significant decrease in strain-to-failure (<4%) under tensile loading and experienced linear elasticity, plastic deformation, and densification under compressive loading. Over the size ranges tested, pore size did not significantly influence the mechanical behavior of the scaffolds on a consistent basis. These results are discussed in regards to use of porous PPP for orthopedic applications and a prototype porous interbody fusion cage is presented.
本研究的重点是制造和研究多孔聚对苯撑（PPP）的机械性能，以将其潜在用作承重骨科生物材料。由于其芳族主链，PPP 具有优异的机械性能，但 PPP 多孔结构的制造和性能尚未得到研究。使用粉末烧结/盐浸技术制造具有小（150-250µm）或大（420-500µm）孔径的定制多孔结构。通过使用 50 至 90vol%的方法系统地改变孔隙率。微计算机断层扫描（µCT）和扫描电子显微镜（SEM）用于验证开胞结构并研究支架的孔形态。通过拉伸和压缩测试来表征实心和多孔 PPP 样品的单轴机械性能。随着孔隙率的增加，模量和强度均降低，与泡沫理论吻合较好。多孔支架在拉伸载荷下失效应变显著降低（<4%），在压缩载荷下经历线性弹性、塑性变形和密实化。在所测试的尺寸范围内，孔径在一定程度上不会显著影响支架的机械性能。这些结果与多孔 PPP 在骨科应用中的使用有关，并提出了一种多孔椎间融合笼的原型。
