Irradiation of chemically crosslinked ultrahigh molecular weight polyethylene
Irradiation of chemically crosslinked ultrahigh molecular weight polyethylene
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DOI：
10.1002/(sici)1099-0488(19960430)34:6
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发表时间：
1996-04
期刊：
影响因子：
--
通讯作者：
F. Shen;H. McKellop;R. Salovey
中科院分区：
文献类型：
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作者：
F. Shen;H. McKellop;R. Salovey
以过氧化氢为氧化剂，采用模压法制备了高分子量聚乙烯人工髋关节髋臼杯。过氧化物交联导致结晶度、峰值熔融温度和重结晶温度降低，以及晶体完整性和尺寸降低。在室温下，在空气气氛中用伽马射线对过氧化物交联的髋臼杯进行灭菌，平均剂量为3.4 Mrad。辐照产生进一步的交联在无定形区域加上广泛的断链的拉紧领带分子，并导致结晶度和晶体的完善性增加。一个显着增加羰基浓度测定辐照标本。一般来说，过氧化物交联降低了辐射对交联网络的影响，因为化学交联稳定了由辐射裂解产生的链片段，并抑制了断裂链从无定形区域的重结晶。化学交联髋臼杯的磨损率要低得多，在50万至100万次循环期间，其磨损率约为对照髋臼杯的五分之一。John Wiley & Sons，Inc.
Acetabular cups for artificial hip joints were prepared by compression molding of ultrahigh molecular weight polyethylene in the presence of peroxide. Peroxide crosslinking led to a decrease in the degree of crystallinity, peak melting temperature, and recrystallization temperature, as well as decreased crystal perfection and size. Peroxide crosslinked cups were sterilized with gamma rays at room temperature in air atmosphere to an average dose of 3.4 Mrad. Irradiation produced further crosslinking in amorphous regions plus extensive chain scission of taut tie molecules and led to increased crystallinity and crystal perfection. A significant increase in carbonyl concentration was determined for irradiated specimens. In general, peroxide crosslinking reduces the effect of irradiation on the crosslinked network, because chemical crosslinking stabilizes chain fragments resulting from radiolytic scission and suppresses recrystallization of broken chains from amorphous regions. Wear rates were much lower for chemically crosslinked cups, which showed about one-fifth of the wear of control cups for the period from 0.5 to 1.0 million cycles. © 1996 John Wiley & Sons, Inc.