UHMWPE Composite Material for Joint Implants

描述（由申请人提供）：在该SBIR第II阶段项目中，将通过创建含碳增强材料的复合材料来改善高分子量聚乙烯（UHMWPE）关节植入物材料的机械和疲劳相关性能。UHMWPE长期以来一直被广泛用作关节植入物的磨损表面，通过交联聚乙烯链进一步提高了其耐磨性。然而，交联过程也降低了一些机械性能，包括韧性、疲劳和屈服强度。通过所述方式将碳增强材料添加到UHMWPE中将提高UHMWPE的强度、抗裂纹扩展性和抗蠕变性，而不会影响其低磨损率。碳增强材料将赋予UHMWPE基质无与伦比的尺寸稳定性和韧性。此外，由于磨损表面仍然（主要）是UHMWPE，因此即使不通过机械增强来改善，也将保持UHMWPE出色的耐磨性。在第一阶段，通过在各种形成条件下制备复合材料，然后评估其机械和摩擦学性能，验证了这些假设中的几个。如果新型UHMWPE材料的性能符合预期，则受益将包括植入物的持久性更高，不易发生机械性失效。因此，复合材料将需要更少的翻修手术，并保持更长的功能，这是一个关键的需求，因为预期寿命的增加导致人们寿命超过植入物。

DESCRIPTION (provided by applicant): In this SBIR Phase II project, the mechanical and fatigue-related properties of ultrahigh molecular weight polyethylene (UHMWPE) joint implant materials will be improved by creating a composite material with carbon reinforcements. UHMWPE has long been widely used as wear surfaces in joint implants, and further improvements to its wear resistance have been obtained by cross-linking the polyethylene chains. However, the cross-linking process also degrades some mechanical properties, including toughness, fatigue and yield strengths. Incorporating carbon reinforcements into UHMWPE through the manner described will improve the strength, crack propagation resistance and creep resistance of UHMWPE without compromising its low wear rate. The carbon reinforcements will impart unmatched dimensional stability and toughness to the UHMWPE matrix. Moreover, as the wear surface remains (primarily) UHMWPE, the outstanding wear resistance of UHMWPE will be maintained, if not improved through the mechanical enhancements. Several of these hypotheses were validated during Phase I by preparing composite materials under various formation conditions, and then assessing their mechanical and tribological properties. Should the new UHMWPE materials perform according as expected, the benefits would include longer-lasting implants that are less prone to mechanically-induced failure. The composite materials would therefore require fewer revision procedures and maintain functionality longer, a critical need as life expectancy increases are causing people to outlive their implants.