γ射线辐射医用级超高分子量聚乙烯自由基的演变  

Evolution of the Radicals inγ-Rays Irradiated Medical Grade Ultra-high Molecular Weight Polyethylene

作　　者：刘思梅 刘伟华[1] 鲁曼丽 张文礼[1] 沈蓉芳 王谋华[1] LIU Simei;LIU Weihua;LU Manli;ZHANG Wenli;SHEN Rongfang;WANG Mouhua(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,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

出　　处：《高等学校化学学报》2021年第8期2602-2608,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:51772308)资助~~。

摘　　要：采用γ射线对医用级超高分子量聚乙烯(UHMWPE)进行辐照处理,利用电子自旋共振波谱仪(ESR)研究了辐照诱导自由基的种类及其在氩气和不同氧分压下的衰减行为.在氩气中,辐射诱导UHMWPE主要产生烷基自由基和烯丙基自由基,总的辐射化学产额约为0.48/100 eV.室温下烷基自由基的稳定性差,其寿命仅有1 d左右.在含氧气氛中,自由基主要通过氧化反应而衰减,其衰减速率随氧分压的增加而增加,半衰期则由1×10^(5)Pa氩气中的224.0 h降至5×10^(5)Pa O_(2)气中的1.8 h.根据此结果推算,室温下陷落在晶区的自由基迁移至微晶表面的速率非常快,仅需小时量级.Medical grade ultra-high molecular weight polyethylene(UHMWPE)was irradiated withγ-rays.The types of irradiation-induced free radicals and their decay behavior under argon and different partial pressures of oxygen were studied by electron spin resonance spectroscopy(ESR).In argon,the alkyl radicals and allyl radicals are the main radical species with a total radiation chemical yield of 0.48/100 eV.Alkyl radicals have poor stability with a life time about 1 d at room temperature.In oxygen-containing atmosphere,free radicals are decayed mainly by oxidation reaction and the decay rate increases with the increase of oxygen partial pressure.The half-life of free radicals decreases from 224.0 h in 1×10^(5) Pa argon to 1.8 h in 5×10^(5) Pa O2.It is estimated that the migration rate of free radicals trapped in the crystal region to the surface of the microcrystalline is very fast at room temperature,on the order of hours.

关 键 词：超高分子量聚乙烯 Γ射线辐照 自由基 氧化 

分 类 号：O631.34[理学—高分子化学]