The Use of TEOST MHT-4 to Measure the Phosphorus Volatility of Engine Oils

Phosphorus is known to poison the exhaust gas catalysts used to control emissions in modern gasoline-fueled passenger car vehicles.Phosphorus volatility has been studied by others as a potential issue related to the compatibility of modern engine oils with exhaust gas catalysts using a modified version of the ASTM D5800(Noack) test as well as the Sequence ⅢG engine test(ASTM D7320).The level of phosphorus volatility in these tests has been shown to be strongly affected by the chemistry of the zinc dialkyldithiophosphate(ZDDP) used in the engine oil formulation.The TEOST MHT-4 test(ASTM D7097) is a high temperature deposit test currently included in the ILSAC GF-4 specification.This bench test simulates the oxidation and deposit-forming characteristics of engine oils in the hot zones of modern high-performance engines and,therefore,was chosen by the author(s) as a tool to investigate differences in phosphorus volatility of modern engine oils.Our investigations demonstrate that the TEOST MHT-4 test is capable of measuring phosphorus volatility of engine oils with very good discrimination and precision;it may be considered for use in future ILSAC standards(e.g.GF-5).

A Multifunctional Borate Ester/Amide for Engine Oils

Global economic and pollution concerns are having a major impact on how modern engine oils are being formulated.Modern engine oil specifications mandate reduced levels of phosphorus and sulfur to protect the efficacy of pollution control devices.In addition,modern engine oil must also be more fuel efficient than earlier generations to reduce greenhouse gas emissions and the impact of high priced gasoline and diesel fuel to the consumer.At the same time,oxidation,wear,and corrosion performance of the oil must not be compromised.Multifunctional additives are useful formulation tools that help formulators meet these tough new challenges.One such additive is the organo-borate ester/amide.Originally conceived as an organic friction modifier,this patented technology is really a multifunctional additive that addresses the global economic and pollution concerns.With the addition of boron,this unique commercial organic friction modifier also imparts antioxidancy,antiwear and anticorrosion properties to engine oil.In addition,the organo-borate ester/amide is compatible with pollution control devices because it does not contain sulfur or phosphorus.Work is on going to uncover additional beneficial properties of this chemistry.

The Stabilization of Vegetable Oil with Antioxidant Combinations

In this paper,the effect of using hindered phenol,zinc dialkyl dithiocarbamate(ZDDC),tolutriazole derivative and combinations thereof to inhibit a blend of commodity Canola Oil and high oleic content soybean oil(1:1) was investigated.Specifically,oils were oxidized by bubbling oxygen through 300 mL samples heated at 95 ℃.Antioxidant depletion rates were indirectly monitored by measuring oxidation induction times(OIT) as determined by Pressure Differential Scanning Calorimetry(PDSC).Preliminary data indicated that oil treated with only ZDDC had the slowest rate of antioxidant depletion.

润滑油抗氧剂协同作用研究

对润滑油的氧化机理做了简要阐述,并根据不同的抗氧作用机理,将抗氧剂分为三类:自由基清除剂(如酚类和胺类抗氧剂)、氢过氧化物分解剂(如氨基甲酸酯)和抗氧协合剂(如不含硫磷的钼酸酯)。利用加压差示扫描量热法(PDSC)对不同类型抗氧剂以及它们之间的协同作用进行了考察。研究表明,作为氢过氧化物分解剂,改进的无灰氨基甲酸酯具有比胺类、酚类抗氧剂更好的性能,这显示了氢过氧化物分解型抗氧剂巨大的应用潜力。研究还表明,具有相同抗氧机理的不同抗氧剂,如酚类和胺类抗氧剂,具有协同作用;不同作用机理的两抗氧剂之间,如自由基清除剂和氢过氧化物分解剂,具有更好的抗氧化协同效果,其中,无灰氨基甲酸酯与烷基化二苯胺抗氧剂具有最佳的抗氧协同效能,可成为高温无灰抗氧剂应用的一个很好选择;不同抗氧机理的三种抗氧剂复合,如烷基化二苯胺,氨基甲酸锌和有机钼酸酯组成的三元复合抗氧剂,具有更为优秀的抗氧化性能。通过不同机理抗氧剂之间的协同,不仅可以获得优秀的抗氧化性能,还可获得附加的极压、抗磨和减摩性能,而且有的减摩、抗磨性能还非常突出,如烷基化二苯胺、氨基甲酸锌和有机钼酸酯组成的三元复合添加剂体系。

提高胺类抗氧剂抗氧化能力的几种有效方法

胺类抗氧剂具有非常好的高温抗氧化能力,其应用越来越广泛。文章介绍了几种提高胺类抗氧剂抗氧化能力行之有效的方法:氧化偶合以及与硫代氨基甲酸酯、硫代氨基甲酸锌、非活性钼酸酯、非活性硼酸酯和碱金属盐添加剂协同。

发动机油非磷抗氧、抗磨、减摩添加剂协同研究

降低发动机油的磷含量,提高燃料经济性,延长使用寿命,已是润滑油升级换代大势所趋。为了降低磷的含量,必须减少二烷基二硫代磷酸锌(ZnDDP)的使用,而二烷基二硫代氨基甲酸锌(ZnDDC)是ZnDDP最理想的替代物。为了提高油品的燃料经济性,需要加入有机钼摩擦改进剂,其中,不含硫磷的钼酸酯添加剂,因其良好的减摩保持性,其应用更为突出。为了满足更苛刻的油品高温性能要求,还必须加入烷基化二苯胺类抗氧剂(AD-PA)。因此有必要对非活性钼、ZnDDC和ADPA之间相互作用进行考察。研究表明,在非活性有机钼、ZnDDC、ADPA的三元添加剂体系中,存在着三种相互配合的协同作用:ZnDDC与非活性有机钼的抗磨协同,非活性有机钼与ADPA的抗氧化协同,以及ZnDDC与ADPA的抗氧化协同。利用非活性有机钼、ZnDDC、ADPA的三元非磷协同复合体系(OD 0401),可以大幅度提高油品的抗氧化性能、减摩性能和抗磨性能,这对发展低磷含量的GF-4和GF-5发动机润滑油具有十分积极的意义。利用该协同复合添加剂OD 0401,还可以有效地提高低档发动机油的抗氧化和抗磨性能。