Experimental study on acrylate of dialkyl dithiophosphoric acid as lubricant additives

Three compounds (ADDP) of dialkyl dithiophosphoric acid and acrylate were synthesized in laboratory. The chemical composition and structure of the ADDP and also their thermal stability were analyzed by means of infrared spectroscopy, mass spectroscopy, element analysis and thermo-gravimetric analysis. The extreme pressure and antiwear properties of these ADDP were comparatively investigated on four-ball machines, in which the worn surfaces of the steel ball were analyzed by SEM method. The results indicated that thermal stability of the synthesized ADDP was better than that of commercial ZDDP. The antiwear properties of ADDP with different alkyl structure were different. The ADDP with branched alkyl possessed better antiwear properties than the ADDP with unbranched alkyl, which will improve the EP and AW properties of lubricate oil with ADDP as additive and reduce additive package dosage, opening vast vistas for its industrial application.