Polyethylene glycol (PEG) diesters from estolides of oleic acid, ricinoleic acid, and 12‐hydroxy stearic acid were used up to 5 wt% additive in petroleum‐derived base oils: 100 N, 220 N, 600 N, PAO 2cSt, PAO 4cst, and PAO 8cSt. The viscosity indices of the petroleum base oils were the lowest (VI = 104–108); the polyalpholefin (PAO) synthetic petroleum‐derived base oils were better (VI = 124–136) and the vegetable‐derived oils were the best (VI = 111–205). 12‐Hydroxystearic estolide PEG 400 diester gave the largest increase in viscosity index in 5% w/w admixtures with PAO 2cSt, 4cSt, 220 N, and 600 N base oils with a 12.3–16.3% increase in viscosity index. Single fatty chain esters had the least impact on viscosity index. As the molecule bulk increased, the viscosity index also increased. This viscosity index effect was demonstrated for the series of monomer to oleic estolide to oleic estolide PEG‐200 diester, which gave viscosity indices of 110, 111–122, respectively, in 5% admixtures with 100 N base oil. The larger the size of the molecule coupled with the polar PEG moiety gave the largest impact on viscosity index improvement where a 5 wt% admixture of 12‐hydroxystearate estolide PEG‐200 diester gave a 25.8% increase in 100 °C viscosity in PAO 2cSt. Incorporation of a dihydroxyl moiety into the molecule at a central side chain location in laurate‐capped ricinoleate estolide PEG‐200 diester did not increase viscosity index of the base oil but greatly reduced its solubility to less than 0.5 wt%.

中文翻译：

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聚乙二醇聚乙二醇二酯的粘度特性

在石油衍生的基础油中使用了高达5 wt％添加剂的油酸，蓖麻油酸和12-羟基硬脂酸雌二醇的聚乙二醇（PEG）二酯：100 N，220 N，600 N，PAO 2cSt，PAO 4cst和PAO 8cSt。石油基础油的粘度指数最低（VI = 104-108）；聚α-烯烃（PAO）合成石油衍生基础油更好（VI = 124-136），而植物衍生油则最好（VI = 111-205）。在含有5％w / w的PAO 2cSt，4cSt，220 N和600 N基础油的混合物中，12-羟基硬脂醇PEG 400二酯的粘度指数增幅最大，粘度指数增幅为12.3-16.3％。单脂肪链酯对粘度指数的影响最小。随着分子体积的增加，粘度指数也增加。这种粘度指数效应在一系列单体到油性内酯到油性内酯PEG-200二酯中得到了证明，在与100 N基础油的5％混合物中，其粘度指数分别为110、111-122。与极性PEG部分偶联的分子较大，对粘度指数的改善影响最大，其中12 wt％的硬脂酸十二醇硬脂酸酯PEG 200二酯的5 wt％混合物使100°C的PAO 2cSt粘度增加了25.8％。在月桂酸酯封端的蓖麻油酸内酯乙交酯PEG-200二酯的中心侧链位置将二羟基部分掺入分子中不会增加基础油的粘度指数，但会大大降低其溶解度至小于0.5 wt％。在100％基础油中加入5％的混合物。与极性PEG部分偶联的分子较大，对粘度指数的改善影响最大，其中12 wt％的硬脂酸十二醇硬脂酸酯PEG 200二酯的5 wt％混合物使100°C的PAO 2cSt粘度增加了25.8％。在月桂酸酯封端的蓖麻油酸内酯乙交酯PEG-200二酯的中心侧链位置将二羟基部分掺入分子中不会增加基础油的粘度指数，但会大大降低其溶解度至小于0.5 wt％。在100％基础油中加入5％的混合物。与极性PEG部分偶联的分子较大，对粘度指数的改善影响最大，其中12 wt％的硬脂酸十二醇硬脂酸酯PEG 200二酯的5 wt％混合物使100°C的PAO 2cSt粘度增加了25.8％。在月桂酸酯封端的蓖麻油酸内酯乙交酯PEG-200二酯的中心侧链位置将二羟基部分掺入分子中不会增加基础油的粘度指数，但会大大降低其溶解度至小于0.5 wt％。