两种无灰型含磷/硫润滑添加剂在菜籽油中的摩擦学性能及膜分析

以合成的两种无灰型含磷/硫化合物为润滑添加剂, 以可生物降解的菜籽油作为基础油, 用四球机研究了体系的抗磨减摩性能, 以X射线光电子能谱(XPS)和X射线吸收精细结构光谱(XANES)对所形成的摩擦膜和热膜进行了表面分析, 并初步探讨了其润滑机理. 摩擦学研究结果表明, 两种含磷/硫化合物作为菜籽油的润滑添加剂时, 具有良好的抗磨减摩性能. XPS和XANES分析结果显示, 摩擦膜和热膜主要由吸附层和反应层组成; 在表面膜中, 磷主要以磷酸盐或焦磷酸盐等形式存在, 而硫主要以硫酸盐的形式存在. 研究结果还表明, 摩擦热在两种不同添加剂的摩擦膜形成过程中发挥着不同的作用.     

有机混合稀土化合物与有机锡化合物作为润滑添加剂的协同效应

用四球摩擦磨损试验机考察了环烷酸混合稀土、环烷酸亚锡及它们的复配物添加在26#白油中的摩擦学性能, 并用俄歇尔电子能谱研究了磨斑表面边界膜的化学组成. 结果表明: 环烷酸亚锡和环烷酸稀土在抗磨性能和减摩性能方面均存在明显的协同效应, 其复配物具有比ZDDP更好的抗磨减摩性能, 有望作为新型的高效多功能润滑添加剂在工业实际中得到应用, 复配物在摩擦表面形成的含稀土元素和锡元素的边界润滑膜是其具有良好摩擦学性能的主要原因.     

异辛基乙二胺-CF3SO3型质子化离子液体作为液体石蜡添加剂的摩擦学性能

以异辛基乙二胺-CF₃SO₃[HEtHex(TFS)]型质子化离子液体作为钢/钢摩擦副的润滑油添加剂, 考察了不同HEtHex(TFS)含量的液体石蜡(LP)在不同温度和载荷下的摩擦学性能. 通过扫描电子显微镜和X射线能谱仪对钢球表面磨斑的形貌及所含元素进行了分析与表征. 结果表明, 加入HEtHex(TFS)添加剂可明显增大LP的最大无卡咬负荷(P_B)值, 改善LP的减摩抗磨性能. HEtHex(TFS)在LP中添加的最佳质量分数为0.75%, 在25 ℃, 294 N时其减摩效果最好; 在25 ℃, 196 N时其抗磨效果最佳. 元素分析结果表明, 加入HEtHex(TFS)添加剂后在钢球表面形成了一层摩擦保护膜, 从而起到了减摩抗磨的作用.     

一种高硫的噻二唑衍生物的摩擦学性能研究

合成了一种高硫含羟基和黄原酸的噻二唑衍生物(ESP),利用四球摩擦磨损试验机考察了其在Corda3970基础油中的摩擦磨损性能,表明所合成的添加剂能够有效的提高Corda 3970基础油的极压和抗磨性能,并且在一定的浓度范围内随着浓度的增加,其抗磨减摩性能增加。通过扫描电镜(SEM)分析了钢球表面形貌及元素分布,发现其主导作用的是边界膜中存在S、O、N活性元素,它们形成复合膜是添加剂具有摩擦学性能的主要原因。     

含氮杂环润滑油添加剂抗摩擦和膜化学性能

制备了N-二异辛基-2-苯并噻唑次磺酰胺(DIMB)和2-硫酮-苯并噻唑-3-甲基鄄巯基乙酸异辛酯(MBES)两种含氮杂环抗磨添加剂, 用SRV型高温摩擦磨损试验机评价它们在芋类基础油中的抗磨减摩性能, 对它们在不同条件下形成的摩擦膜进行X射线吸收精细结构光谱(XANES)分析, 用原子力显微镜(AFM)分析摩擦膜的表面形貌. 结果表明, 添加剂DIMB和MBES具有很好的抗磨性能, 但没有减摩性能. XANES分析结果表明, 添加剂MBES形成的摩擦膜完全由硫酸亚铁组成, 而添加剂DIMB形成的摩擦膜的次表面和本体主要由二硫化铁组成, 未测量到硫酸盐或硫化铁, 但摩擦膜表面部分被氧化成硫酸亚铁. AFM 测试结果表明, 与含1.5%(w)二烷基二硫代磷酸锌(ZDDP)抗磨添加剂的钢块磨损表面相比较, 分别含1.5%(w)DIMB 和1.5%(w)MBES添加剂的钢块磨损表面出现了深而宽的“犁沟”.     

双/三氮杂冠醚化合物的合成及其作为摩擦改进剂的性能研究※

现代汽车工业的发展以及环保法规的日益严格对车用润滑油的性能提出了更高要求, 摩擦改进剂在提高发动机油减摩性能及燃油经济性方面发挥着重要作用. 有机钼化合物作为目前使用最为广泛的摩擦改进剂, 会增加油品热氧化沉积物的生成, 且油品氧化会导致其减摩性能下降. 针对摩擦改进剂所存在的诸如有害元素、灰分及活性吸附位点有限等问题, 设计并合成了两种双/三氮杂冠醚化合物, 将活性氮原子及长链烷基引入冠醚结构中以提高吸附性能和油溶性, 并研究其作为摩擦改进剂的减摩和抗磨性能. 结果表明, 所合成双/三氮杂冠醚能有效降低油品的摩擦系数和磨损率, 其中含有吡啶结构的三氮杂冠醚表现出更优的摩擦学性能, 可使摩擦系数和磨损率相对于基础油分别降低8.8%和42%. 机理分析表明, 所合成的双/三氮杂冠醚化合物能够在钢表面发生不同程度的吸附, 并进一步发生摩擦化学反应形成润滑保护膜, 防止滑动表面微凸体的直接接触进而改善摩擦学性能.     

正丁基硫代磷酸酯的合成及其摩擦学性能研究

用MS、 FT-IR等方法对合成的三正丁基一硫代及四硫代磷酸酯进行了结构表征,并在四球摩擦磨损试验机上考察了其在液体石蜡中的摩擦学性能;用扫描电镜(SEM)和X射线光电子能谱(XPS)对钢球磨痕表面做了分析.结果表明: 对于钢-钢摩擦副,合成的两种硫代磷酸酯可以显著提高液体石蜡的极压抗磨性能,但不能改善其减摩性能.钢球磨损表面XPS和SEM分析结果表明,添加剂分子在金属表面发生物理或化学吸附,并导致金属表面的腐蚀和摩擦化学反应.     

磷酸镧和二烷基二硫代磷酸锌及其复合添加剂对通用锂基脂摩擦学性能的影响

合成了稀土化合物磷酸镧，利用四球摩擦磨损试验机考察了磷酸镧，商品添加剂二烷基二硫代磷酸锌及两者的复合添加剂对通用锂基脂摩擦学行为的影响，用扫描电子显微镜和X射线光电子能谱仪（XPS）观察分析了钢球磨损表面形貌及其元素的化学状态。研究结果表明：磷酸镧和二烷基二硫代磷酸锌均可增加通用锂基脂的承载能力，磷酸镧可提高锂基脂的减摩抗磨能力，二烷基二硫代磷酸锌对基础脂的减摩抗磨性能的作用效果不稳定。含上述添加剂的锂基脂在摩擦副表面发生化学吸附或摩擦化学反应，生成由锂基脂和添加剂共同作用形成的边界润滑膜，从而改善锂基脂的润滑性能。     

硫化菜籽油的催化合成及其摩擦学特性

以精制菜籽油为原料,天然丝光沸石为催化剂,研究了硫化菜籽油的催化合成,并借助FTIR测试技术分析了产物的化学结构. 通过四球摩擦磨损试验机考察了其摩擦学性能,同时对磨痕表面进行了XPS及显微分析,探讨了其润滑机理. 结果表明,随硫粉投料量的增大,菜籽油不饱和度逐渐降低,在丝光沸石催化下,硫化反应收率可达98%以上;含硫量从0增大到9.96%,硫化菜籽油的摩擦学性能明显提升,摩擦系数由0.085降为0.025,磨斑直径由0.56 mm降至0.42 mm,最大无卡咬负荷(PB值)由549 N升至745 N,烧结负荷(PD值)由1 960 N升至2 254 N;其润滑机理初步归结于硫化菜籽油在摩擦副表面上形成的吸附油膜,以及摩擦过程中由于摩擦化学反应形成的摩擦转移膜共同起减摩耐磨和极压作用.     

胎儿脐带血铅水平与钙、锌、铁的关系研究

目的研究胎儿脐带血中的铅与钙、锌、铁的含量以及两两之间的相关性。方法采用原子吸收光谱法对398例脐带血铅和钙、锌、铁的含量进行测定,并对它们进行相关性分析。结果 398例脐带血铅和钙、锌、铁的质量浓度分别为铅(37.96±17.78)μg/L、钙(1.51±0.29)mmol/L、锌(30.01±11.14)μmol/L、铁(8.63±1.39)mmol/L。线性回归分析显示:铅与钙(r=-0.563,P0.01)、铅与锌(r=-0.424,P0.01)有相关性,铅与铁无显著相关(r=0.018,P0.05)。结论随着胎儿体内血铅水平的上升,二价元素钙、锌含量有下降趋势,即中毒元素铅会干扰胎儿体内的必需二价元素的代谢。     

Cu掺杂TiO_2薄膜的摩擦学性能

采用溶胶-凝胶法在普通玻璃基底上制备了纯TiO2和Cu掺杂的TiO2(Cu-TiO2)纳米结构薄膜,利用X射线光电子能谱(XPS)、原子力显微镜(AFM)、粉末X射线衍射(XRD)及UMT-3摩擦磨损试验机考察了Cu掺杂量对薄膜组成、结构、表面形貌及摩擦学性能的影响.结果表明,相比于纯TiO2薄膜,Cu掺杂TiO2纳米薄膜平整、均匀,具有较好的耐磨减摩性能.Cu掺杂量的多少直接影响Cu-TiO2薄膜的减摩抗磨性能,当Cu掺杂量为5%(摩尔分数)时,Cu-TiO2膜具有最佳的耐磨寿命和最低的摩擦系数.     

Tribochemistry of phenol and benzyl alcohol between YG8 self-mated interfaces

In this work, the tribological performance of mixed lubricant consisting of phenol and benzyl alcohol between YG8 self-mated interfaces was systematically investigated under 98 N and 1450 rpm. The results showed that with increasing concentration of phenol in the mixed lubricant, the friction coefficient initially decreases and then increases; however, anti-wear performance initially was enhanced and then weaken. As the concentration of phenol was 1.0 wt.%, the tribo-system exhibited the lowest friction coefficient and wear scar diameter. TEM, SEM and XPS techniques were employed to probe the possible tribological mechanism sliding in the mixed lubricant containing 1.0 wt.% of phenol. The phenol effectively slowed down the oxidation of the mixed lubricant, combination of friction-induced tungsten oxides and carbon quantum dots, assuring the tribo-system still in mixed lubrication condition, which made the tribo-system maintain low friction coefficient and wear.     

Preparation of WS2 nanocomposites via mussel-inspired chemistry and their enhanced dispersion stability and tribological performance in polyalkylene glycol

A novel biomimetic surface modification method utilizing mussel-inspired chemistry was used to prepare tungsten disulfide (WS₂) nanocomposites, which enhanced the dispersion stability and tribological performance of WS₂ in polyalkylene glycol (PAG). Herein, WS₂-polydopamine-methoxypolyethylene glycol amine (WS₂-PDA-MPGA) was first synthesized via mussel-inspired chemistry and used as a lubricant additive in PAG. After modification, the dispersion stability of WS₂ nanosheets in PAG was obviously improved. Moreover, the tribological performance of WS₂-PDA-MPGA in PAG at high temperature was evaluated by the oscillating reciprocating tribometer. Compared to pure PAG, the lubricant composition containing WS₂-PDA-MPGA exhibited excellent performance in friction reduction and anti-wear properties at high temperature. The optimal tribological performance could be obtained when the percentage of additives was 0.9?wt%. The tribological results indicate that WS₂-PDA-MPGA, with its good dispersion stability, has better friction reduction and anti-wear properties than does WS₂ in PAG base oil. The chemical composition analysis of the wear surface indicated that a stable protective film had been formed by physical adsorption and tribo-chemical reactions. Therefore, the surface modification strategy is an effective way to improve the dispersion stability of WS₂ in PAG, which can be expanded application of WS₂ in the tribological field.     

含氯磷硼酸酯聚合物的摩擦性能

合成了标题聚合物，对其进行了IR表征。利用四球试验机测定其作为润滑剂的摩擦学性能。结果表明，含磷硼酸酯的最大无卡咬负荷值大于含氯硼酸酯，而且减摩抗磨效果好；含长链疏水基团的硼酸酯的最大无卡咬负荷比短链疏水基团的高，承载能力高。EDAX能谱分析表明，其抗磨性能与摩擦表面中存在硼、氯、磷活性元素有关。     

Synthesis of ricinoleate anion based ionic liquids and their application as green lubricating oil additives

Ricinoleate anion based ionic liquids (ILs) were synthesized from four different nitrogen containing cationic counterparts such as tetrabutylammonium, tetrapropylammonium, cetyltrimethylammonium, imidazolium. Tribological performance of synthesized ILs were evaluated using four ball tribo tester by blending with two lubricant base oils namely epoxy2-ethylhexyl esters of karanja fatty acids (EKE) and dioctyl sebacate (DOS). Antiwear behaviour was explored by varying different factors including concentration, applied load and rotation speed. It was found that the synthesized ILs in base oil significantly reduced the wear scar diameter by 17–25% at 0.8 wt% and a remarkable reduction in wear scar diameter was observed for all the tested applied load (40 to 80 kg) and rotation speed (1200 to 1742 rpm). Further, the load carrying capacity of base oil was improved by 25–43% at 1.25 wt% of IL dosage. The imidazolium cation containing IL outperform tribological performance among all the ILs being studied. The morphology of worn surface after the wear tests and deposition of elementals on the worn surface lubricated with neat base oil and IL blended base oil was studied by scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX).     

有机小分子染料和聚阳离子分子超薄膜的制备及其摩擦学性能研究

制备了以有机小分子染料酸性红 1 8为阴离子、以聚烯丙基氯化铵和聚乙烯亚胺为聚阳离子的分子沉积膜 ,用紫外可见分光光度计、接触角测定仪和椭圆偏振光测厚仪对所制备的超薄膜进行了表征 .用DF PM型动 静摩擦系数精密测定装置考察了超薄膜的摩擦学性能 ,采用扫描电子显微镜对薄膜的磨痕表面进行了观察 .结果表明 ,所制备的超薄复合沉积膜具有良好的减摩和耐磨性能     

A low-temperature extraction-solvothermal route to the fabrication of micro-sized MoS2 spheres modified by Cyanex 301

Mono-dispersed molybdenum disulfide micro-spheres with the diameter of 1-3 μm have been successfully synthesized via extraction-solvothermal method at 150 °C. The extractant Cyanex 301 (di-(2,4,4-trimethylpentyl) dithiophosphinic acid) acted as phase transferring agent, reductant, sulfur source and morphology-controlling agent in the whole procedure. The obtained MoS₂ micro-spheres were characterized by XRD, EDS, SEM, TEM, HRTEM, IR, UV-Vis and TG, respectively. The influences of reaction conditions were discussed while a mechanism was proposed to explain the formation of the micro-spheres. Moreover, the tribological properties of liquid paraffin (LP) containing Cyanex 301-modified MoS₂ micro-spheres were also evaluated on a four-ball machine, showing that the obtained MoS₂ product was an excellent oil additive in LP and such lubricant had good anti-wear and friction-reducing properties.