Tribology of Polymer Nanocomposites

聚合物纳米复合材料的摩擦学

• 批准号: 0099649
• 负责人: Wallace Sawyer
• 金额: $ 7.5万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0099649&HistoricalAwards=false
• 关键词: Tribology; Polymer; Nanocomposites

0099649SawyerThis SGER award will support a feasibility study of the effect of nanoparticle strenghthening of polymers for tribological applications. There are strong indications that polymers filled with hard nanoparticleswill exhibit significant improvements in tribological performance ascompared to traditional filled polymers. Polymers are widely used inbearing applications because they provide quiet continuous operation, have alow coefficient of friction, absorb vibrations, are compliant andnon-abrasive to the counterface, can be easily manufactured, areinexpensive, non-corrosive, and are generally biocompatible. The challengein designing bearings with homogeneous polymeric materials is their low wearresistance (high wear rates). Hard filler particles are frequently added toimprove the wear resistance, however these hard filler particles increasethe abrasive wear to the counterface and increase the sliding coefficient offriction. Lubricious fillers are also added to polymers and under certainoperating conditions can reduce the wear rate and the coefficient offriction, however a constant supply of lubricous filler must be available atthe wear surface and these materials are frequently sensitive to theenvironment. The ideal filler for polymers would be inert, reinforcing,non-abrasive, and reduce the coefficient of friction. There is goodevidence that nanoparticle filled polymers may be this 'ideal' composite.For example, recent studies have shown that the wear resistance can increasein polymer composites filled with hard nanoparticles, while at the same timethe wear of the counterbody decreases and the sliding coefficient offriction decreases. This type of tribological behavior will have an impactin polymeric bearings covering the spectrum from industrial applicationsneeding dry sliding bearings, to orthopaedic implant materials, toself-lubricating bearings for space environments.In order to design composites with the optimum properties and predictperformance, however, some severe limitations must be overcome. First, ourunderstanding of the mechanisms contributing to wear performance in filledpolymers is poor. For example, the role of the filler / matrix interfaceand the effect of particle size has not been well studied nor are thereappropriate models that consider the interface or size of the filler.Secondly, it is unclear for non-lubricious nanoparticles what the mechanismis that lowers the coefficient of friction. Finally, nanoparticle filledpolymers have not comprehensively explored for wear applications despite thestrong evidence suggesting large improvements in performance.The overall scientific goal of the project is to gain a fundamentalunderstanding of the wear mechanisms in filled polymers by a) experimentallyisolating the effects of particle size (10 nm to 10 micrometers), particleaspect ratio (1 to 1000), dispersion, filler / matrix interface, and matrixproperties on performance, and 2) obtaining a parametric understanding ofthe correlation between wear behavior and other mechanical properties, 3)modeling of the wear properties.***

0099649SAWYERTHIS THIS SGER Award将支持对聚合物纳米颗粒strenghthenening对摩擦学应用的影响的可行性研究。 有力的迹象表明，填充有硬纳米颗粒的聚合物将在与传统填充的聚合物相比的摩擦学性能方面具有显着改善。 聚合物被广泛使用，因为它们提供了安静的连续操作，具有极高的摩擦系数，吸收振动，合规性和对反面的侵蚀，可以轻松制造，具有质感，非腐败性，并且通常是生物相容性的。 使用均匀的聚合物材料设计轴承的挑战是它们的磨损较低（高磨损率）。 经常添加硬填充颗粒以增强耐磨性，但是这些硬填充颗粒会增加对逆面的磨料磨损，并增加了滑动系数。 还添加了润滑性填充剂，并且在某些操作条件下可以降低磨损速率，并且系数的off缩合率，但是持续的润滑填充剂必须在磨损表面上可用，并且这些材料经常对环境敏感。 聚合物的理想填充物将是惰性，加强，非侵蚀性的，并减少摩擦系数。 良好的证据是，纳米颗粒填充的聚合物可能是这种“理想”的复合材料。例如，最近的研究表明，耐磨性可以增加充满硬纳米颗粒的聚合物复合材料，而在相同的时间磨损时，反体的磨损也会减少，滑动系数降低。 这种类型的摩擦学行为将产生涵盖工业应用的谱系范围，从工业应用，干燥的滑动轴承，骨科植入物材料，用于空间环境的抗润滑轴承。在空间环境中，润滑轴承。在设计具有最佳性质的复合材料并预测性能，但是，某些严重的限制必须是克服限制。 首先，我们对有助于在填充物中磨损性能的机制的理解很差。 例如，填充 /矩阵间互动的作用粒径的效果尚未得到很好的研究，也不适合考虑填充物的界面或尺寸的更典型的模型。首先，对于非润滑的纳米颗粒而言，尚不清楚降低摩擦系数的非润滑纳米颗粒。 最后，尽管有证据表明性能有很大的改善，但纳米颗粒填充聚合物并未对磨损应用进行全面探索。该项目的总体科学目标是通过a）通过实验性地（10 nm至10微米）的效果（1000米）（1 000年）（1到1000）（1 000年），以实验性地理解填充聚合物中的磨损机制的基本知识。对性能的基质杂质，以及2）获得对磨损行为与其他机械性能之间相关性的参数理解，3）磨损特性的建模。***