电子束辐照超高分子量聚乙烯在加速老化过程中的自由基演变  

Evolution of free radicals in ultra-high molecular weight polyethylene irradiated by an electron beam during accelerated aging process

作　　者：王静 鲁曼丽 沈蓉芳 王谋华[1] 胡志杰 张文礼[1] WANG Jing;LU Manli;SHEN Rongfang;WANG Mouhua;HU Zhijie;ZHANG Wenli(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China;Beijing Antong Yitai Medical Technology Co.,Ltd.,Beijing 101300,China)

机构地区：[1]中国科学院上海应用物理研究所,上海201800 [2]中国科学院大学,北京100049 [3]北京安通忆泰医疗科技有限公司,北京101300

出　　处：《辐射研究与辐射工艺学报》2024年第2期18-26,共9页Journal of Radiation Research and Radiation Processing

基　　金：国家自然科学基金(12375357)资助。

摘　　要：经过辐照处理的医用超高分子量聚乙烯(UHMWPE)必须通过加速老化试验的验证才能达到植入人体使用的要求,但在加速老化过程中,UHMWPE材料的自由基演化机制尚不明确。本研究从自由基角度出发,对现有加速老化方法的效果进行了系统分析。利用电子顺磁共振波谱研究了电子束辐照交联UHMWPE在加速老化过程中的自由基浓度和组成的变化,分析了自由基在该过程中的演变机理,对比分析了自由基在室温空气和70℃氮气中的演变机理。结果表明:加速老化评估方法有很大的局限性,辐照交联UHMWPE表层和内部的自由基在室温空气环境中的演变与在加速老化环境中的演变有显著区别,氧诱导自由基(OIR)的生成率在室温空气环境中约为2%,在加速老化环境中约为0.3%。OIR自由基在室温空气中会稳定存在,而在加速老化环境中会被快速氧化。Irradiated medical ultra-high molecular-weight polyethylene(UHMWPE)must be validated through accelerated aging tests to meet the requirements for implantation into the human body.However,the free radical evolution mechanism of UHMWPE during accelerated aging remains obscure.We systematically analyzed the effectiveness of existing accelerated aging methods from the perspective of free radicals.The changes in the concentration and composition of the free radicals present in electron-beam-irradiated crosslinked UHMWPE during accelerated aging were evaluated using electron paramagnetic resonance spectroscopy.The evolution mechanisms of the free radicals during this process were analyzed;in addition,the mechanisms occurring in room-temperature air and under a 70℃nitrogen atmosphere were analyzed and compared.The results revealed that accelerated aging evaluation methods had significant limitations.The evolution mechanism of the free radicals present on the surface of irradiated crosslinked UHMWPE as well as inside it in room-temperature air were significantly different from that observed in the accelerated aging environment.In addition,the generation rate and oxidation degree of the oxygen-induced free radicals in the two environments are different.

关 键 词：超高分子量聚乙烯 电子束辐照 自由基 氧化反应 

分 类 号：TL13[核科学技术—核能科学]