Biotribological properties of UHMWPE grafted with AA under lubrication as artificial joint
Biotribological properties of UHMWPE grafted with AA under lubrication as artificial joint
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DOI：
10.1007/s10856-013-4970-x
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发表时间：
2013-06
期刊：
影响因子：
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通讯作者：
Yaling Deng;D. Xiong;Kun Wang
中科院分区：
文献类型：
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作者：
Yaling Deng;D. Xiong;Kun Wang
在人工髋关节中，聚乙烯磨损颗粒引起的骨溶解是一个严重的问题。为了使超高相对分子质量聚乙烯(UHMWPE)人工关节轴承表面长期保持低摩擦磨损性能，采用紫外光辐照的方法在UHMWPE粉末表面接枝了亲水性丙烯酸(AA)，并对改性粉末进行了热压处理。在往复式摩擦试验机上考察了改性超高相对分子质量聚乙烯(UHMWPE)在小牛血清、生理盐水和蒸馏水润滑条件下长期摩擦时的摩擦学性能。傅里叶变换红外光谱测试表明，通过光引发接枝聚合，AA成功地接枝到了UHMWPE粉末表面。接枝后UHMWPE的接触角由83°降至35°，表面润湿性得到有效改善。改性后的试件抗拉强度降低。UHMWPE-g-PAA在小牛血清、生理盐水和蒸馏水润滑下的摩擦系数和磨损率均低于未处理的UHMWPE。随着接枝率的增加，UHMWPE-g-PAA的磨损率先减小后增大。接枝率为3.5%的改性UHMWPE磨损率最低，仅为未处理UHMWPE的四分之一。UHMWPE散装材料中的水合PAA聚合物刷子在长期滑动过程中提供持续的润滑。
Osteolysis caused by wear particles from polyethylene in the artificial hip joints is a serious issue. In order to endow the low friction and wear of the bearing surface of ultra-high molecular weight polyethylene (UHMWPE) artificial joint for a longer term, hydrophilic acrylic acid (AA) was grafted on UHMWPE powders with the method of ultraviolet irradiation and then the modified powders were hot pressed. The tribological properties of modified UHMWPE sliding against CoCrMo metallic plate on reciprocating tribometer under calf serum, saline and distilled water lubrication during a long-term friction were investigated. The measurement of Fourier-transform infrared spectroscopy indicates that AA is successfully grafted on the surface of UHMWPE powders by photo-induced graft polymerization. Contact angles of UHMWPE are decreased from 83° to 35° by grafting and the surface wettability is effectively improved. The tensile strength of modified sample decreases. The friction coefficient and wear rate of UHMWPE-g-PAA under calf serum, saline and distilled water lubrication are lower than that of untreated UHMWPE. With the increase of grafting ratio, the wear rate of UHMWPE-g-PAA decreases firstly and then increases. The modified UHMWPE with grafting ratio of 3.5 % has the lowest wear rate, which is just quarter of the untreated UHMWPE. The hydrated PAA polymer brushes enclosed in the UHMWPE bulk material provide continuous lubrication during long term sliding.