The polyalkylene glycol (PAG) lubricants are widely used as gear, bearing and compressor oils. Indeed, the base PAG oil with additives can be used both in engine oil or transmission oil as additive compound or as base lubricant in refrigerant systems. They are designed to provide outstanding benefits in terms of efficiency, long oil life, and equipment protection. These fully synthetic lubricants were developed for use under operating conditions beyond the capabilities of other synthetic lubricants and mineral oils. Their low pour points ensure excellent low-temperature fluidity. On the other hand the disadvantage of the PAG oils is that they are hygroscopic, i.e. they absorb and bind moisture from the ambient air. In this paper the results from tribological testing of PAG oil featuring 46 cSt at 40°C with solid (graphene oxide) and liquid (ionic liquids) additives are proposed. Preliminary experiments with ball-on-flat setup by using a reciprocatory tribometer have been carried out on the base oil PAG 46 blended with 1-Ethyl-3-methylimidazolium acetate or graphene oxide, alternatively. In this way the influence of each additive has been investigated. Based on this information the aim of this research is to test the hybrid formulations and to verify potential improvements on anti-friction and anti-wear PAG 46 behaviour in a broad range of lubrication regimes. The experimental tests have been carried out by using a rotational disc tribometer in ball-on-disc configuration. The results confirm the reduction of friction coefficient provided by GO dispersion, along with the settlement drawback, more marked at higher lubricant temperature. On the other hand, the inclusion of ionic liquid allows enhancing of frictional behaviour at higher temperature as compensation of reduced GO action in such operating conditions. Finally, the tested formulations showed very weak protection against surface wear.
Tribological performance of graphene oxide and ionic liquid as friction modifiers in PAG base oil
D'AGOSTINO, Vincenzo;PISATURO, MARIO;SENATORE, ADOLFO
2016-01-01
Abstract
The polyalkylene glycol (PAG) lubricants are widely used as gear, bearing and compressor oils. Indeed, the base PAG oil with additives can be used both in engine oil or transmission oil as additive compound or as base lubricant in refrigerant systems. They are designed to provide outstanding benefits in terms of efficiency, long oil life, and equipment protection. These fully synthetic lubricants were developed for use under operating conditions beyond the capabilities of other synthetic lubricants and mineral oils. Their low pour points ensure excellent low-temperature fluidity. On the other hand the disadvantage of the PAG oils is that they are hygroscopic, i.e. they absorb and bind moisture from the ambient air. In this paper the results from tribological testing of PAG oil featuring 46 cSt at 40°C with solid (graphene oxide) and liquid (ionic liquids) additives are proposed. Preliminary experiments with ball-on-flat setup by using a reciprocatory tribometer have been carried out on the base oil PAG 46 blended with 1-Ethyl-3-methylimidazolium acetate or graphene oxide, alternatively. In this way the influence of each additive has been investigated. Based on this information the aim of this research is to test the hybrid formulations and to verify potential improvements on anti-friction and anti-wear PAG 46 behaviour in a broad range of lubrication regimes. The experimental tests have been carried out by using a rotational disc tribometer in ball-on-disc configuration. The results confirm the reduction of friction coefficient provided by GO dispersion, along with the settlement drawback, more marked at higher lubricant temperature. On the other hand, the inclusion of ionic liquid allows enhancing of frictional behaviour at higher temperature as compensation of reduced GO action in such operating conditions. Finally, the tested formulations showed very weak protection against surface wear.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
