UHMWPE用于生物工程的摩擦磨损研究

世界各国一般都采用UHMWPE作人工关节假体中的髋臼材料，人工关节松动的主要原因是UHMWPE的细小磨损颗粒引起骨溶解致使假体松动。为了研究髋臼材料的耐磨性，减少磨损颗粒的产生，笔者对国内分子量最高（497万）的UHMWPE模压成型试样和机加工成型试样的表面摩擦磨损性能进行了研究。此外，还研究了分子量对UHMWPE磨损量的影响以及UHMWPE在生理盐水润滑下的摩擦性能。     

试验环境温度对小牛血清边界润滑条件下超高分子量聚乙烯往复磨损行为的影响

采用自行研制的往复摩擦磨损试验机,在法向栽荷为50 N、往复频率1 Hz、摩擦副接触形式为圆环外圆周/平面、初始线接触长度为6 mm,相对湿度为80%、体积含量25%小牛血清去离子水溶液边界润滑的试验条件下,研究试验环境温度对超高分子量聚乙烯(UHMWPE)与铁合金配副的往复摩擦磨损性能的影响,并利用扫描电子显微镜观察37℃时磨损表面形貌.结果表明:试验环境温度θ由10℃升高至30℃,UHMWPE/钛合金摩擦副的平均摩擦因数μa呈明显下降趋势,由30℃升高至37℃时,μa开始缓慢上升,UHMWPE的体积磨损量Wv随试验环境温度θ变化也呈现相似的规律;磨损机制主要表现为磨料磨损.     

改性超高分子量聚乙烯的摩擦磨损性能研究

通过添加聚丙烯(PP)和交联聚丙烯(PP-X)对超高分子量聚乙烯(UHMWPE)进行改性,研究了UHMWPE及其共混物的摩擦磨损性能.结果表明,在200 r/min滑动速度下,当PP或PP-X的质量分数为30%时,UHMWPE/PP的摩擦因数降至0.13,降幅达38.1%,磨痕宽度降至5.05 mm;UHMWPE/PP-X的摩擦因数降到0.12,降幅达42.9%,磨痕宽度则降至4.50 mm,UHMWPE/PP-X具有更优异的摩擦磨损性能.负载增大,UHMWPE及其共混物的摩擦磨损性能降低.磨损时间小于60 min,UHMWPE及其共混物的摩擦因数和磨痕宽度变化不大;超过60 min,摩擦因数和磨痕宽度均增大,UHMWPE/PP-X的增幅最小.高速滑动下UHMWPE/PP-X的摩擦磨损性能最高.     

超高分子量聚乙烯纤维/有机玻璃复合材料摩擦磨损性能研究

用真空浸渍法成功制备出了超高分子量聚乙烯纤维／有机玻璃(UHMWPE／PMMA)复合材料，并对基体材料PMMA，单向超高分子量聚乙烯纤雏／有机玻璃复合材料以及三维编织超高分子量聚乙烯纤维／有机玻璃(即UHMWPE3D／PMMA)复合材料的摩擦磨损性能进行了研究。实验证明UHMWPE／PMMA复合材料具有优良的摩擦磨损性能。经过纤维增强的复合材料的摩擦磨损性能优于基体材料，三维编织纤维增强的复合材料其磨损远小于单向纤维增强的复合材料，但其摩擦系数没有显著变化。     

超高分子量聚乙烯摩擦磨损特性

用磨损试验机对超高分子量聚乙烯（UHMWPE）进行滑动磨损试验，考察了对磨钢轮的粗糙度，对磨时间及载荷对磨损及摩擦系数的影响。结果表明，UHMWPE具有较好的耐磨性，与45^#钢轮对磨时其磨损量很小，但其耐硬质的SiC颗粒磨损的性能不佳；UHMWPE在跑合期及加速磨损期摩擦系数较大，而在稳定磨损阶段则较低；载荷的加大会增大UHMWPE的摩擦系数。     

氧化硅陶瓷高温摩擦学性能

本文研究热压氮化硅陶瓷与３Ｃｒ２Ｗ８Ｖ钢组成的销－盘摩擦副，在空气中非润滑条件下，４００￣８００℃不同载荷（４９￣３４３Ｎ）的摩擦磨损性能；测定了磨擦系数的Ｓｉ３Ｎ４销的磨损因子；通过对Ｓｉ３Ｎ４磨损面的ＳＥＭ形貌观察、Ｘ射线相结构分析，探讨了陶瓷销的磨损机理。     

超高分子量聚乙烯的滑动摩擦磨损研究

本文在塑料滑动摩擦磨损试验方法的基础上,研究超高分子量聚乙烯（UHMWPE）与砂纸进行滑动摩擦磨损的过程,为快速、合理的评价UHMWPE板材料、管材料的耐磨性能提供方法。实验过程中,随着摩擦距离改变,UHMWPE的磨损量与磨痕宽度变化明显,而且磨损表面表现出不同的摩擦学特征。另外,摩擦过程生热严重,容易发生氧化反应。通过磨粒磨损、粘着磨损、疲劳磨损等机理对UHMWPE摩擦磨损过程进行了说明。     

摩擦偶面对聚酰亚胺粘结MoS_2涂层摩擦学性能的影响

制备聚酰亚胺粘结二硫化钼固体润滑涂层,在MM-200摩擦磨损试验机上考察涂层和不同偶面摩擦时的摩擦特性,通过SEM研究了涂层表面磨损形貌及偶面转移膜的形貌,试验结果显示偶面材料对转移膜的生成及涂层摩擦磨损性能影响很大。     

超高分子量聚乙烯在海水介质中的摩擦磨损性能研究取得重要进展

近日,由中国科学院兰州化学物理研究所薛群基院士、阎逢元研究员带领的科研人员研究了海水润滑条件下超高分子量聚乙烯fUHMWPE）分别与易腐蚀对偶（GCr15钢）和耐腐蚀对偶（化学镀Ni—P镀层）对摩时的摩擦磨损行为,并与其在干摩擦、水润滑和质量分数为3.5％氯化钠溶液润滑条件下的摩擦磨损性能进行了对比。     

超高分子量聚乙烯的改性研究

通过添加PP和自制交联聚丙烯(PP-X),使用双辊开炼和Haake密炼的方法对超高分子量聚乙烯(UHMWPE)进行改性,并通过万能材料试验机、熔体流动速率仪和摩擦磨损试验机等系统研究了UHMWPE、UHMWPE/PP、UHMWPE/PP-X的力学性能、熔体流变性能及摩擦磨损性能等.结果表明,当PP和PP-X的质量分数小于等于30%时,UHMWPE的力学性能得到了一定程度的改善,熔体流动性能增加,摩擦磨损性能有较大提高.     

纳米Al_2O_3填充超高分子量聚乙烯的生物摩擦磨损性能研究

用纳米Al2O3对人工关节软骨UHMWPE进行填充改性,在生理盐水润滑条件下,评价了其摩擦磨损性能。结果表明,纳米Al2O3的加入,在一定程度上提高了UHMWPE的硬度,与钛合金对磨时的摩擦系数随Al2O3含量(<10%)的增加而增加;与不锈钢对磨时,摩擦系数有所增加;不同Al2O3含量(<10%)的UHMWPE,磨损率比纯UHMWPE低。纯UHMWPE的磨损表现为明显的犁沟以及塑性变形,加入纳米Al2O3的UHMWPE的磨损主要表现为磨粒磨损和轻微的塑性变形。     

Improvement of the tribological behavior of ultra‐high‐molecular‐weight polyethylene by incorporation of poly (phenyl p‐hydroxyzoate)

Ultra‐high‐molecular‐weight polyethylene/poly (phenyl p‐hydroxyzoate) composites (coded as UHMWPE/PPHZ) were prepared by compression molding. The effects of the poly (phenyl p‐hydroxyzoate) on the tribological properties of the UHMWPE/PPHZ composites were investigated, based on the evaluations of the tribological properties of the composites with various compositions and the examinations of the worn steel surfaces and composites structures by means of scanning electron microscopy and transmission electron microscopy. It was found that the incorporation of the PPHZ led to a significant decrease in the wear rate of the composites. The composites with the volume fraction of the PPHZ particulates within 45% ～ 75% showed the best wear resistance. The friction coefficient of the UHMWPE/PPHZ composites decreased with increasing load and sliding velocity, while the wear rates increased with increasing load. This was attributed to the enhanced softening and plastic deformation of the composites at elevated load or sliding velocity. The UHMWPE/PPHZ composites of different compositions had differences in the microstructures and the transfer film characteristics on the counterpart steel surface as well. This accounted for their different friction and wear behaviors. The transfer film of the UHMWPE/PPHZ composites appeared to be thinner and more coherent, which was largely responsible for their better wear resistance of t composite than the UHMWPE matrix. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2336–2343, 2005     

PAM填充超高相对分子质量聚乙烯的摩擦性能

用聚丙烯酰胺(PAM)对超高相对分子质量聚乙烯(UHMWPE)进行了共混改性,研究了PAM填充量对其在干摩擦及水润滑状态下摩擦的性能影响。并用扫描电子显微镜观察了材料摩擦表面磨痕形貌。研究发现,在水润滑条件下,加入少量的PAM,能够明显降低材料的相对摩擦系数,继续增加PAM的填充量,摩擦系数变化较小并逐渐趋于稳定。     

Molecular dynamics simulation of α-ZrP/UHMWPE blend composites containing compatibilizer and its tribological behavior under seawater lubrication

In this work, blended composites with ultra-high molecular weight polyethylene (UHMWPE) as matrix polymer, α-zirconium phosphate (α-ZrP) as filler, and sodium polyacrylate (PAANa) as compatibilizer were prepared. The interfacial interaction between PAANa as a compatibilizer and the components of α-ZrP/UHMWPE was studied by molecular dynamics simulation. The friction and wear behavior of the GCr15 ball/composite friction pair under seawater lubrication under different loads were explored, and the friction and wear mechanism were analyzed. The results show that PAANa as a compatibilizer can effectively improve the interfacial interaction force between components of PAANa/α-ZrP/UHMWPE composites. The composites exhibited different trends regarding the relationship between tribological properties and α-ZrP content under various loads. The wear mechanism of composites under low load is mainly represented by extrusion deformation. With the increase of load, the wear mechanism of composites gradually changed into adhesive wear and abrasive wear (depending on the content of α-ZrP). This work provides a theoretical basis for preparing and applying other α-ZrP/polymer blend composites.     

Fabrication of Polyimide-Modified UHMWPE Composites and Enhancement Effect on Tribological Properties

Polyimide-modified ultrahigh molecular weight polyethylene (UHMWPE) composites were fabricated by hot-press molding process. Mesoscopic morphologies of polyimide/UHMWPE blending systems show high compatibility between the phases of polyimide and UHMWPE when the weight ratio of polyimide is no more than 50?wt%. Investigation of the tribological properties with a reciprocating ball-on-flat contact tribometer shows that the polyimide filler has important effects on the friction and wear behavior of UHMWPE composites. Compared to pure UHMWPE, the composite with 50?wt% polyimide improved tribological properties best and exhibited 43.1% reduction in friction coefficient and 66.7% reduction in wear volume loss.     

UHMWPE的臭氧化降解及摩擦磨损性能研究

研究了臭氧化反应对超高摩尔质量聚乙烯（UHMWPE）熔体流动性、摩擦磨损性能以及结晶性能的影响。经臭氧化反应，UHMWPE发生降解，粘均摩尔质量从2650kg／mol降低到566kg／mol，熔体质量流动速率从0增加到0．28g／10min。随臭氧化处理时间的增加，材料摩擦系数和磨损量基本不变，UHMWPE优异的磨擦磨损性能得以保持。DSC分析结果表明，随臭氧化反应时间的增加，UHMWPE熔融焓增加，结晶度增加。