Li Yinbiao, Duan Weipeng
School of Mechanical Engineering, Wuxi Institute of Technology Wuxi 214121 China
RSC Adv. 2024 Oct 11;14(44):32133-32141. doi: 10.1039/d4ra05720a. eCollection 2024 Oct 9.
In this work, the influence of accelerated aging on the thermo-mechanical behavior and biotribological properties of an irradiation cross-linked GO/UHMWPE nanocomposite after VE diffusion was investigated, including through differential scanning calorimetry (DSC), gel content, FT-IR characterization, oxidation index, ball indentation hardness, and especially the biotribological properties. The results show that accelerated aging increased the melting point and crystallinity of the nanocomposite, but resulted in a decrease in thermal stability and gel content. The oxidation index increased by 60.2% and the hardness decreased by 18.1%. In particular, the friction coefficient and wear rate increased by 99.5% and 87.4% respectively. A simple VE diffusion process had no obvious effect on the melting point, crystallinity, thermal stability, gel content and hardness, but the oxidation resistance and biotribological performance were improved to a certain extent. On the contrary, when VE exists in the accelerated aging process, the above properties are significantly improved. In particular, the oxidation index decreased by 21.1%, and the friction coefficient and wear rate decreased by 33.7% and 26.4%, respectively. After accelerated aging, fatigue wear and abrasive wear are the main wear forms, while VE plays the function of reducing friction and wear. Besides, the anti-friction and wear resistance mechanism of VE during the accelerated aging process was also illustrated.
在本工作中，研究了加速老化对经维生素E（VE）扩散后的辐照交联氧化石墨烯/超高分子量聚乙烯纳米复合材料的热机械行为和生物摩擦学性能的影响，包括通过差示扫描量热法（DSC）、凝胶含量、傅里叶变换红外光谱（FT-IR）表征、氧化指数、球压痕硬度，尤其是生物摩擦学性能。结果表明，加速老化提高了纳米复合材料的熔点和结晶度，但导致热稳定性和凝胶含量降低。氧化指数增加了60.2%，硬度降低了18.1%。特别是，摩擦系数和磨损率分别增加了99.5%和87.4%。简单的VE扩散过程对熔点、结晶度、热稳定性、凝胶含量和硬度没有明显影响，但抗氧化性和生物摩擦学性能在一定程度上得到了改善。相反，当VE存在于加速老化过程中时，上述性能得到显著改善。特别是，氧化指数降低了21.1%，摩擦系数和磨损率分别降低了33.7%和26.4%。加速老化后，疲劳磨损和磨粒磨损是主要磨损形式，而VE起到了减摩耐磨的作用。此外，还阐述了VE在加速老化过程中的减摩耐磨机理。
