申请人:TRENT UNIVERSITY
公开号:US20170137739A1
公开(公告)日:2017-05-18
The disclosure generally provides branched diester compounds having exceptional low-temperature and flow properties. The disclosure also provides uses of the branched diester compounds in lubricant compositions, for example, as a base oil, and in other applications where their low-temperature and flow properties can be employed beneficially. The disclosure also provides efficient and green methods for making the branched diester compounds.
In certain embodiments, a vegetable oil-based diester (1,6-hexyldioleate) was branched with propanoic acid (C3) using a green synthetic approach involving solvent-free and catalyst-free epoxide ring opening followed by in situ normal esterification. A total of three branched ester derivatives possessing varied numbers of internal protruding branched ester groups and hydroxyl groups were obtained. All of the pure branched derivatives were comprised of mixtures of positional isomers and/or stereoisomers. Differential scanning calorimetry (DSC) showed that regardless of the composition inhomogeneity of each branched derivative, crystallization was suppressed completely in all of the branched compounds, and they all demonstrated glass transitions below −65° C.
Without being bound by any theory, it is believed that this unique thermal behavior is attributed to the internal protruding branched moieties and hydroxyl groups, which dramatically slowed down mass transfer starting with the least branched compound (2-branched derivative). The viscosity of the branched compounds was one order of magnitude larger than that of the starting di ester due to the increased branching and increased resistance to flow associated with hydrogen bonding introduced by the OH groups. Overall, these branched diesters demonstrated superior low temperature and flow properties comparable to existing non-sustainable commercial lubricants and analogous biobased materials which makes them suitable alternatives for use in lubricant formulations particularly in high performance industrial gear and bearing lubricants.
本文披露了具有卓越低温和流动性能的分支二酯化合物。本文还提供了分支二酯化合物在润滑剂组合物中的用途,例如作为基础油,在其他应用中可以受益于其低温和流动性能。本文还提供了制备分支二酯化合物的高效和环保方法。在某些实施例中,使用无溶剂和无催化剂的环氧环开和原位正酯化的绿色合成方法,将植物油基二酯(1,6-己二酸二正辛酯)与丙酸(C3)分支化。共获得了三种分支酯衍生物,具有不同数量的内部突出的分支酯基和羟基。所有纯分支衍生物均由位置异构体和/或立体异构体的混合物组成。差示扫描量热法(DSC)表明,无论每个分支衍生物的组成不均匀性如何,所有分支化合物中都完全抑制了结晶,并且它们都表现出低于-65°C的玻璃转变温度。在没有受到任何理论约束的情况下,人们认为这种独特的热行为归因于内部突出的分支基团和羟基,这些基团从最不分支的化合物(2-分支衍生物)开始显著地减缓了质量转移。由于由OH基团引入的氢键,分支化合物的粘度比起始二酯高一个数量级,由于分支的增加和流动阻力的增加。总的来说,这些分支二酯表现出与现有非可持续商业润滑剂和类似的生物基材料相当的优越低温和流动性能,使它们成为润滑剂配方中的合适替代品,特别是在高性能工业齿轮和轴承润滑剂中。