【作者】 田言；

【导师】 黄玉东； 任南琪；

【作者基本信息】 哈尔滨工业大学 ， 化学工程与技术， 2009， 博士

【摘要】 改善材料的摩擦、磨损性能和润滑性能，不仅可以满足机械设备向高速、重载和高精度方向发展的需要，而且可以延长机械设备的使用寿命，对节约资源和环境保护意义重大。本论文针对现有极压抗磨添加剂产品存在的不足，基于原位摩擦化学理论，从表面修饰剂的选择入手，系统开展了材料设计、制备与性能评价等方面的研究工作。在合成表面修饰剂的基础上，制备了表面修饰纳米硼酸镧和纳米二硫化钼极压抗磨添加剂，通过对其结构表征和极压抗磨性能的研究，研制出具有抗磨减摩和原位摩擦化学处理双重功能的极压抗磨添加剂硼钼剂，并进行了应用研究。以五硫化二磷、十八烷醇、吡啶为主要原料，优化了表面修饰剂PyDDP的制备工艺，合成了本研究所用的表面修饰剂二烷基二硫代磷酸吡啶（PyDDP），对其产率影响因素和相关工艺条件进行了研究。分别以硬脂酸和PyDDP为表面修饰剂，以硼砂和硝酸镧为原料，在醇-水混合溶剂中合成了硬脂酸修饰纳米硼酸镧和PyDDP修饰纳米硼酸镧，并优化了合成工艺参数。以PyDDP为表面修饰剂，以钼酸钠、盐酸羟胺、硫化钠、稀硫酸为原料，合成了PyDDP修饰纳米MoS2。采用IR、TG-DTA、XRD等分析方法，对三种表面修饰纳米微粒进行了表征，并分析了表面修饰纳米硼酸镧和纳米二硫化钼的形成机制，结果表明，所制备的微粒是一种表面为有机物修饰且存在无机核的无机/有机复合微粒。采用SEM、EDXA等方法对钢球的表面形貌、表面元素进行了分析，研究了所制备的三种微粒的摩擦学机理。结果表明，硬脂酸根离子St-和PyDDP中的DDP-均可与La3+反应生成稳定的化合物LaSt3或者LaDDP3。在摩擦副表面起主要作用的是La、B、Mo等元素，镧和硼在基体表面形成复杂的化学反应膜和渗透层是添加剂具有良好抗磨性能的重要原因。而表面修饰纳米二硫化钼的减摩抗磨机理主要是将滑动摩擦部分转变为滚动摩擦的“滚珠轴承作用”，因而在添加剂浓度较低的情况下其极压性能和减摩性性能也比较突出。采用四球实验研究了所制备三种纳米微粒的极压抗磨性能，研究结果表明：三种微粒均具有良好的减摩和抗磨性能，可以降低摩擦、减少能量消耗，并可减少磨损、增强材料使用寿命，具有优异的节能环保特性。硬脂酸修饰纳米硼酸镧与PyDDP修饰纳米硼酸镧相比，后者在较低添加量下即具有较好的抗磨性能；PyDDP修饰纳米硼酸镧与纳米MoS2相比，前者减摩性能较好，而后者抗磨性能较好，为了兼顾减摩和抗磨性能，将两者按一定比例复配制成硼钼剂，研究结果表明硼钼剂具有更好的极压抗磨性能和降低摩擦系数的功能。以所制备的硼钼剂作为极压抗磨剂，以四球试验考察了其在成品发动机油中的摩擦学性能。实验室评价表明，其抗磨性与承载能力同市售发动机油相当，减摩性优于市售同类产品。台架试验结果表明：硼钼剂可以提高成品发动机油的抗磨性能和减摩能力，且其承载能力没有降低。本论文所制备的无机纳米极压抗磨剂具有性能优良、使用稳定、环保高效的特点，具有良好的应用前景，同时，本论文研究结果也验证了应用表面修饰无机纳米极压剂实现原位摩擦化学处理观点的正确性。更多还原

【Abstract】 Modifying the antiwear and lubricating property of material has an important effectboth on the energy, resources savings and environmental protection. It not only satisfiesthe tendency of higher speed，heavier load and higher accuracy of the machine inventedwith modern scientific technology, but also lengthens their service life. According to theshortcomings of the current extreme pressure-antiwear additives product, two kinds ofextreme pressure-antiwear additives (surface modified lanthanum borate andmolybdenum disulfide) were prepared to realize material with the property of antiwearand anti friction and in-situ tribochemical treatment. A borate-molybdenum (B-Mo)agent was finally prepared and the application of the agent was investigated.Phosphorus pentasulfide, octadecanol and pyridine were used as basic material tosynthesize the main surface modifying agent of this paper: pyridinium dialkyldithiophosphate (PyDDP). The technological conditions were thoroughly studied andfonfirmed. Using stearic acid and PyDDP, respectively, as modifying agent, borax andlanthanum nitrate as raw material, the stearic acid and PyDDP modified lanthanumborate nanoparticles were synthesized, respectively, in mixed alcohol-water solvents.Using PyDDP as the modifying agent, sodium molybdate, hydroxylamine hydrochloride,sodium sulfide and dilute sulfuric acid as raw material, the surface modifiedmolybdenum disulfide (MoS2) nanoparticles were synthesized. The technologicalparameters of the proceses were optimized. Infrared spectrum (IR), thermal gravity anddiffertial thermal analysis (TG-DTA), X-ray diffraction (XRD), Ultraviolet spectrum (UV)were used to characterize the structure of the three kind nanoparticles. The formationmechanism of the surface modified nanoparticles was initially analyzed and proposedand results showed that the three kinds of nanoparticles were modified by a layer oforganic material with an inorganic core. The tribological properties of three synthesizednanoparticles were studied by four-ball test. The surface morphology and elements wereanalyzed by SEM and EDXA. The tribological mechanism was discussed and impliedthat all synthesized nanoparticles had good extreme pressure property.The tribological properties showed that all synthesized stearic acid and PyDDPmodified lanthanum borate nanoparticles had good extreme pressure characteristics. BothSt-and DDP-can react with La3+ions to form thermol stable LaSt3or LaDDP3. The mainelements which affect on the friction properties might be owing to La，B and Mo. Thechemical reacted film and the physical penetrated layer formed by La and B in thefriction surface is the main contribution to the extreme pressure properties of themodified lanthanum borate nanoparticles. But for surface modified molybdenum disulfide (MoS2), the transformation of roll friction to sliding friction might be the mostimportant effect which induced good friction abilities even in low agent concentration.Four ball experiments were used to investigate the extreme pressure properties ofthe particles. Compared with steric acid modified lanthanum borate, PyDDP modifiedlanthanum borate possessed better anti-friction ability even in lower content in base oil.Further more, it was founded that PyDDP modified lanthanum borate and molybdenumdisulfide were favored on extreme pressure properties and friction reducing propertiesrespectively both in lower contents. So a new agent of B-Mo was formed with bi-component and possesses satisfied extream pressure properties and lower frictioncoefficient.Taking PyDDP modified PyDDPBMo with good extreme pressure property asextreme pressure-antiwear additive, the tribological properties of engine oil product werestudied. Results indicated that PyDDPBMo could improve the abrasion resistance andanti-friction of engine oil. The engine oil complex additive was prepared usingPyDDPBMo as one compoment. Laboratory test showed that the abrasion resistance andcarrying capacity of PyDDPBMo was also equivalent to that of other similar products inmarket.更多还原