Two phosphonium cation-based ionic liquids used as lubricant additive

Battez

et al. 2020

Self Cite

Two new ionic liquids ([N 6,6,6,6 ][C 8:0 ] and [N 6,6,6,6 ][C 16:0 ]) synthetized from fatty acids through a salt metathesis reaction were both characterized from a physicochemical and tribological point of view. Density, viscosity, corrosion activity and thermal stability tests were performed before making tribological tests under ball-on-disc both unidirectional (with fixed and variable slide-to-roll ratio) and reciprocating configuration. The main results of this work were the following: the longer the length of the alkyl chain of the anion the lower both viscosity and density and higher both viscosity index and thermal stability; these ionic liquids (ILs) are not corrosive; the [N 6,6,6,6 ][C 16:0 ] behaved better changing from elastohydrodynamic to mixed lubrication regime at lower speeds; their antiwear behavior at high load seems depend on their viscosity (for tests made at room temperature) and thermal stability and IL-surface interaction (for tests made at high temperature).

Section: Introductionmentioning

confidence: 99%

Two fatty acid anion-based ionic liquids - part I: Physicochemical properties and tribological behavior as neat lubricants

Sernaglia

Battez

et al. 2020

Self Cite

“…The main drawbacks of the ionic liquids are: high price, low solubility in common non-polar oils, possibility of forming HF due to water exposition of ionic liquids containing anions such as [PF6]and [BF4] -, and problems related to toxicity and/or biodegradability due to the presence of halogens or metals in their composition. With regard to solubility problems, ionic liquids based on phosphonium cation has shown excellent results as additive in non-polar oils [10,13,[22][23][24][25]. On the other hand, new ionic liquids have been synthesized avoiding the presence of halogens and metals in order to overcome the formation of…”

Section: Introductionmentioning

confidence: 99%

Physicochemical, traction and tribofilm formation properties of three octanoate-, laurate- and palmitate-anion based ionic liquids

Battez

Rivera

et al. 2019

Self Cite

Three new ionic liquids with different anions and the same cation were synthesized from fatty acids through a metathesis reaction. All the ionic liquids were identified via NMR and FTIR and several properties (density, viscosity, thermal, and environmental) were measured. Traction tests were performed under different entrainment speeds (10-2000 mm/s), at slide-roll ratio (SRR) of 50% and 30 N-load, and at different temperatures (40, 60, 80 and 100 ºC) using a mini-traction machine (MTM). Tribofilm formation tests were also made in the MTM at 50 N-load, 150 mm/s of entrainment speed, at SRR of 50% and temperature of 100 ºC, for 60 minutes. This work showed that the alkyl chain length in the anion affects properties such as viscosity, toxicity, biodegradability and lubrication. Viscosity decreased with increasing alkyl chain length but only below 60ºC, at higher temperatures the viscosity values of the ionic liquids converge. The toxicity and biodegradability increased with the alkyl chain length, but these novel ionic liquids are much better from both toxicity and biodegradability points of view than the [N8881][TFSI] ionic liquid, which contains the same cation and anion not coming from fatty acids. The ionic liquids at low temperature (40 ºC) performed under elastohydrodynamic lubrication and changed to mixed lubrication at higher temperatures and decreasing speeds, according to the alkyl chain length of each anion. All ionic liquids adsorbed on the steel surfaces, and the tribofilm thickness and the kinetics of formation were different.

“…This is why much research focuses on their use as a lubricant additive in order to enhance their cost effectiveness [26]. Moreover, the solubility problems of ILs in common non-polar oils have tended to direct research towards their utilization as additives at low concentrations in these base stocks [29,[39][40][41][42][45][46][47][48][49][50] and few studies have tested their use as additive of a non-polar fully-formulated oil [51][52][53]. Otherwise, various research studies focused on polar oils have used ionic liquids as additive with the aim of overcoming the solubility problem [54][55][56][57][58][59][60][61][62][63][64][65][66][67][68].…”

Section: Introductionmentioning

confidence: 99%

Environmental properties of phosphonium, imidazolium and ammonium cation-based ionic liquids as potential lubricant additives

Oulego

Ramos

et al. 2018

Self Cite

This research compares the environmental properties (bacterial toxicity and biodegradability) of 12 ionic liquids-ILs-(7 phosphonium, 2 imidazolium and 3 ammonium cation-based ones), potentially applicable as lubricant additive, with two types of the traditional lubricant additive ZDDP. Aquatic toxicity was determined by means of Vibrio fischeri and Escherichia coli bacteria, while biodegradability was evaluated through biological oxygen demand (BOD 5) and chemical oxygen demand (COD) measurements. Regarding toxicity results, [P 4442 ][DEP] was the least toxic IL (acute 3 according to GHS) for both bacteria, whereas ZDDP fell into the acute 1 category (very toxic). All samples tested turned out to be poorly biodegradable, showing BOD 5 /COD values below 0.1. Two ILs showed better combined tribological and environmental properties than ZDDP.