Turell Mary Beth, Bellare Anuj
Department of Orthopaedic Surgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, MRB 106, Boston, MA 02115, USA.
Biomaterials. 2004 Aug;25(17):3389-98. doi: 10.1016/j.biomaterials.2003.10.027.
Ultra-high molecular weight polyethylene (UHMWPE) has gained worldwide acceptance as a bearing material used in orthopaedic implants. Despite its widespread use, inherent properties of the polymer continue to limit the wear resistance and the clinical lifespan of implanted knee and hip prosthetics containing UHMWPE components. The degree of crystallinity of UHMWPE is known to strongly influence several of its tensile mechanical properties such as Young's modulus, yield stress, strain-hardening rates, work of fracture and ultimate tensile properties. In this study, medical grade UHMWPE was subjected to four different crystallization conditions resulting in UHMWPE with a range of crystalline morphologies. Thereafter, the crystalline nanostructure was quantitatively characterized using a combination of ultra-small angle X-ray scattering and differential scanning calorimetry. Low-voltage scanning electron microscopy was employed as a supplementary technique to compare the crystalline morphology resulting from each crystallization condition. In addition, uniaxial tensile tests were performed to assess the effects of crystallization conditions on the mechanical properties of UHMWPE. This study showed that while crystallization conditions strongly influenced the morphology of UHMWPE, in most cases the mechanical properties of the material were not significantly affected.
超高分子量聚乙烯（UHMWPE）作为一种用于骨科植入物的轴承材料已在全球范围内得到认可。尽管其应用广泛，但该聚合物的固有特性仍限制了含UHMWPE部件的植入式膝关节和髋关节假体的耐磨性及临床使用寿命。已知UHMWPE的结晶度会强烈影响其多项拉伸力学性能，如杨氏模量、屈服应力、应变硬化率、断裂功和极限拉伸性能。在本研究中，医用级UHMWPE经历了四种不同的结晶条件，从而得到具有一系列结晶形态的UHMWPE。此后，结合超小角X射线散射和差示扫描量热法对结晶纳米结构进行了定量表征。采用低电压扫描电子显微镜作为补充技术，比较每种结晶条件产生的结晶形态。此外，进行了单轴拉伸试验，以评估结晶条件对UHMWPE力学性能的影响。本研究表明，虽然结晶条件强烈影响UHMWPE的形态，但在大多数情况下，材料的力学性能并未受到显著影响。
