Structure-behavior relationship of lanthanum dialkyldithiophosphate as lubrication additive
1. School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. School of Material Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China）
Abstract：The structure-behavior relationship of lanthanum dialkyldithiophosphate is studied. Ten LaD-DPs with different alkyl chains were prepared. The properties of antiwear and extreme pressure of LaD-DPs as lubricating oil additive in 500SN base oil were investigated by four-ball machine, and the effects of the length of alkyl chain and the structure of primary or secondary alkyl of lanthanum dialkyldithiophosphate additive on the properties of friction-wear and extreme pressure were explored. The results showed that, for carbon numbers in alkyl in a range of 3 to 8, the additives exhibit excellent properties of antiwear and extreme pressure. The antiwear abilities are improved obviously with the increase of carbon number in alkyl. Moreover, the properties of friction and wear of secondary alkyl LaDDPs have advantages over that of primary alkyl LaDDPs. It is suggested that extreme pressure abilities decrease with the increase of carbon numbers in alkyl and the alkyl construction has little effect on the extreme pressure property.
2008, Vol. 29 
