硼酸酯添加剂的制备及摩擦学特性的研究

发布时间：2019-01-09 10:40

【摘要】：有机硼酸酯因其低毒性、无异味和优良的极压抗磨性能而受到研究人员的广泛关注,被称为“绿色”添加剂。然而,硼酸酯的水解敏感性常常导致润滑油中含有不溶物或沉淀,这主要是因为其中的缺电子硼元素易于与空气中的水分子结合而导致酯键断裂。为此,引入氮元素以弥补硼元素的缺电子性、增加添加剂分子的空间位阻,便成为解决这一问题的重要手段。基于这一思路,制备了四种硼酸酯添加剂YXB、YX2、YX3和SNPA,制备了一种含钼添加剂YXM,作为对比,采用了工业上常用添加剂ZDDP。应用红外光谱仪(FT-IR)和元素分析(EA)手段对合成产物进行了表征,测试了它们的油溶性和水解稳定性。采用四球机测试了添加剂的摩擦学性能。结果表明:1.合成的含硼、钼添加剂具有优良的极压性能。当添加量为3.0%时,添加剂YXB、YXM的PB值相比于基础油PAO分别增加了 175%、194%,添加剂SNPA的PB值相比于基础油PAO增加了 203%。2.合成的含硼、钼添加剂具有良好的抗磨性能。当YXM的添加量为2.5%时,WSD达到最小值0.44mm,相比于基础油减小了 42.1%;当SNPA的添加量为2.5%时,WSD达到最小值,为0.49mm,相比于基础油减小了 29.6%。3.合成的含硼、钼添加剂具有较好的减摩性能。在添加量为1.0%时,YXB和YXM对应的平均摩擦系数分别为0.0766、0.0796,相比于基础油PAO分别减小了24.4%和21.4%;在添加量为2.5%时,SNPA对应的平均摩擦系数为0.0787,相比于基础油减小了 22.3%。4.添加剂SNPA与ZDDP的对比结果显示,前者的极压、抗磨与减摩性能更为优良。采用SEM和XPS研究了磨损表面的形貌及摩擦膜的化学组成。SEM图片显示,在含添加剂的油样润滑状态下,磨损表面更加光滑,表面擦伤更加轻微;而在基础油润滑状态下,磨损表面则严重擦伤。XPS结果表明,磨损表面存在有机分子碎片的物理化学吸附,生成了一些摩擦化学产物,如Fe203、BN、B203、Mo03和FeS04等,这些吸附物和反应生成物一起构成了成分复杂的摩擦膜以保护接触表面。
[Abstract]:Organic borate is widely concerned by researchers because of its low toxicity, no odour and excellent extreme pressure and antiwear properties, so it is called "green" additive. However, the hydrolytic sensitivity of borate esters often leads to insoluble or precipitate in lubricating oils, which is mainly due to the easy binding of boron deficiency elements with water molecules in air, resulting in ester bond breakage. Therefore, the introduction of nitrogen to make up for the electron deficiency of boron and the increase of steric resistance of additive molecules have become an important means to solve this problem. Based on this idea, four borate additives, YXB,YX2,YX3 and SNPA, were prepared and a molybdenum containing additive YXM, was prepared as a comparison. The commonly used additives in industry, ZDDP., were used. The synthesized products were characterized by infrared spectroscopy (FT-IR) and elemental analysis (EA), and their oil solubility and hydrolysis stability were tested. The tribological properties of additives were tested by four ball machine. The results show that: 1. The additives containing boron and molybdenum have excellent extreme pressure properties. When the additive dosage was 3.0, the PB value of additive YXB,YXM increased by 175% compared with that of base oil PAO, and the PB value of additive SNPA increased by 203%. 2. 2 compared with base oil PAO. The synthetic additives containing boron and molybdenum have good antiwear properties. When the addition of YXM is 2.5, the minimum value of WSD is 0.44 mm, which is 42.1 mm lower than that of base oil. When the amount of SNPA added is 2.5, WSD reaches a minimum of 0.49mm, which is 29.60.3mm less than base oil. The synthetic additives containing boron and molybdenum have good antifriction properties. The average friction coefficient of YXB and YXM is 0.076 6 ~ 0.0796 when the addition amount is 1.0, which is 24.4% and 21.4% less than that of base oil PAO, respectively. The average friction coefficient of SNPA is 0.0787 when the addition amount is 2.5. Compared with base oil, the friction coefficient decreases 22.3.4. The comparison of additive SNPA and ZDDP shows that the extreme pressure, antiwear and antifriction of the former are better. The morphology of the wear surface and the chemical composition of the friction film were studied by SEM and XPS. SEM images show that the wear surface is smoother and the surface scratch is more slight under the lubricating condition of the oil sample containing additives. The XPS results show that there exists physical and chemical adsorption of organic molecular fragments on the worn surface, resulting in some tribological chemical products, such as Fe203,BN,B203,Mo03 and FeS04, etc. Together with the reactants, these adsorbents form a complex friction film to protect the contact surface.
【学位授予单位】：天津科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE624.82

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