Experimental Study On Tribological Properties Of Random Copolyether Aqueous Solutions

With the energy shortage and constant enhancement in environmental consciousness worldwide, water-based lubrication is the ideal alternative resource of mineral oil, which plays a more important role in equipment lubrication and metal-working. For dealing with the poor film-forming and lubrication performance of aqueous solutions, the different mass concentration aqueous solutions of propylene glycol random copolyether (PPE), butanol random copolyether (BPE), dodecanol random copolyether (CPE) and lauric acid random copolyether (LPE) are prepared. Friction-reducing, anti-wear, rheology and film-forming performances of random copolyether aqueous solutions are tested.Rubbing pairs of steel/aluminum and steel/steel are selected. Friction-reducing and anti-wear performances of random copolyether aqueous solutions are tested on MS-T3000 friction and wear tester. The influences of mass concentration, load, velocity and surface roughness are discussed. The surface morphology of samples are measured by the Phase shift MicroXAM-3D and Scanning Probe Image Processor software. The results show that LPE is effective on improving the friction-reducing and anti-wear. Friction-reducing performances get better as the mass concentration and load increasing. The reason is that polarity adsorption groups in LPE acqueous solutions forming thick chemical adsorbed film and physical adsorbed film adsorb in metal surfaces. The films have better friction-reducing and anti-wear performances by seperating friction surfaces.The rheometry performances of random copolyether aqueous solutions are tested in Physica MCR301 rotating rheometer. The relations between dynamic viscosity and shear rate are analysed at the different concentration and temperature. The results show that random copolyether show Newton's flow characteristic at 25℃. when the temperatures reach cloud points, PPE aqueous solution is Newton characteristic, but others still show non-Newtonian flow characteristic. Dynamic viscositys get up by the increasing of temperature and mass concentration, and the lubrication performances of water get better.At half and full immersion lubricating states, the film-forming performances of random copolyether aqueous solutions are tested in nanometer lubrication film measuring instrument of NGY-6 with the different mass concentration and velocity. The results show that film-forming of water is improved by random copolyether. The film-forming of PPE aqueous solutions is better than others, film thickness increases as the increase of mass concentration, and form thin film lubrication condition. The film-forming of LPE aqueous solutions is not good, but stable, and form boundary lubrication.So we can reach a conclusion that the study provides a new direction for water-soluble lubricating additives. It also offers experimental basis and theoretical foundation for aqueous solution reasearch. The random copolyether aqueous solution have the rosy prospect of the utilization in industrial application. Fifty-two figures, twelve tables, ninety-nine references.