油酸甲酯型含氮硼酸酯的合成及其抗磨减摩特性

Synthesis of Boric Acid Ester Containing Nitrogen From Methyl Oleate and Its Tribological Performance

通过环氧化处理、环氧基非对称亲核开环反应和酯化反应在油酸分子双键位置引入含氮硼酸基团,制备了一种油酸甲酯型含氮硼酸酯类化合物(BN),并采用傅里叶红外光谱仪表征了合成产物的化学结构。将BN添加于液体石蜡和菜籽油2种不同基础油中,采用四球摩擦试验机测定了其抗磨减摩特性。结果表明,油酸甲酯经硼氮化改性后,极压抗磨性能明显提高。与添加油酸甲酯的液体石蜡相比,添加BN的液体石蜡的PB值从470N增加到696N,提高48.40%;PD值从1148N增加到1569N,提高36.67%;磨斑直径从0.55mm减小到0.44mm,减少20%。与添加油酸甲酯的菜籽油相比,添加BN的菜籽油的PB值从539N增加到921N,提高70.87%;PD值从1236N增加到2452N,提高98.38%;磨斑直径从0.56mm减小到0.44mm,减少21.43%。合成的硼氮化改性油酸甲酯可以作为菜籽油和液体石蜡等基础油优良的极压抗磨添加剂,且菜籽油对其感受性要好于液体石蜡。

A methyl oleate containing boron and nitrogen named BN was synthesized via epoxidation- reaction, epoxy-group nucleophilic ring-opening reaction and esterification to introduce a group of boric acid containing nitrogen to the double bond of methyl oleate molecule. The chemical structure of synthesized product was characterized by infrared-spectroscopy. The tribological performance of synthesized product in two base oils, liquid paraffin and rapeseed oil, was investigated by four ball friction test machine. The results showed that the anti-wear ability and extreme-pressure performance of methyl oleate after chemical modification was enhanced significantly. Compared to 470 N of PB, 1148 N of PD and 0.55 mm of WSD for the liquid paraffin with methyl oleate added, the PB, PD and WSD of liquid paraffin with BN added were 696 N, 1569 N and 0.44 mm, increased by 48.40%, 36.67% and dropped by 20%, respectively. Compared to 539 N of PB, 1236 N of PD and 0.56 mm of WSD for the rapeseed oil with methyl oleate added, the PB, PD and WSD of rapeseed oil with BN added were 921 N, 2452 N and 0.44 mm, increased by 70.87%, 98.38% and dropped by 21.43%, respectively. The synthesized product BN could be used as a lubricant additive for rapeseed oil and liquid paraffin, and the tribological performance of rapeseed oil with BN was better than that in liquid paraffin.