Quaternary phosphonium-based ionic liquids: Thermal stability and heat capacity of the liquid phase

Ferreira, André F.; Simões, Pedro; Ferreira, Abel G.M.

doi:10.1016/j.jct.2011.08.019

Cited by 101 publications

(73 citation statements)

References 55 publications

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“…These values ranges between 485 K and 709 K and it can be clearly seen that the anion influence on the thermal stability of ILs is higher than the cation one, being ILs with [NTf2] -and [OTf] -anions the most stable; meanwhile dicyanamide, nitrate and acetate based ILs were the least stable, agreeing with the main observations for thermal stability of ILs in literature [8][9][10][11].…”

Section: Resultssupporting

confidence: 90%

<strong>SHORT-TERM THERMAL STABILITY OF IONIC LIQUIDS</strong>

Parajó

López

Salgado

2017

Proceedings of the 21st International Electronic Conference on Synthetic Organic Chemistry

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Abstract:It has been frequently said that onset temperatures obtained from dynamic thermogravimetric analysis can be used to estimate the short-term thermal stability of materials and also the relative thermal stability.In this work the relative thermal stability was studied through dynamic analysis under the same experimental conditions for 50 Ionic Liquids (ILs). Several families with fixed anions and different cations and vice versa were chosen to have a comprehensive knowledge of thermal properties of ILs depending on the ions selection. Non-isothermal scans were performed under air atmosphere and a heating rate of 10 K · min -1 for all the selected ILs.It was observed that the anion influence on the thermal stability is stronger than the cation one,

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Section: Resultssupporting

confidence: 90%

<strong>SHORT-TERM THERMAL STABILITY OF IONIC LIQUIDS</strong>

Parajó

López

Salgado

2017

Proceedings of the 21st International Electronic Conference on Synthetic Organic Chemistry

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“…This behaviour is possibly related to the influence of a more reactive phosphate type anion [13], causing alkyl phosphates to pyrolyze readily at temperatures of 300 ºC and above [74] and thus resulting in an extra peak. Early weight losses in all samples are probably related to the impurities (between 2-5% in weight according to Table 1) present in the ionic liquids used in this study [15];…”

Section: Kinetic Parameters and Modellingmentioning

confidence: 88%

“…Apart from factors related to the sample itself, such as the presence of moisture and/or impurities (which could lead to a significant decrease in the stability), taking into account the operating factor (type of sample, sample size and heating rate) is also required. This coexistence of different factors limits the comparison of data from different sources [15,77], with the experimental atmosphere used in TGA studies being one of the most important factors affecting the results [65,83].…”

Section: Thermo-oxidative Decompositionmentioning

confidence: 99%

“…Significant research has been focused on the thermophysical properties of imidazolium-based ILs [11,12], but there are only a few studies focused on a novel class of ILs based on phosphorous quaternary cations [13,14]. The phosphorus atom allows for bonding with different substituents, giving a great number of different structures and physicochemical properties [15,16].…”

Section: Introductionmentioning

confidence: 99%

“…An appropriate estimation of this property is a key factor in many engineering applications, including lubrication [17]. Despite the fact that a significant number of works have been focused on the study of thermal degradation of ILs [18][19][20][21][22][23][24][25], only a few of them have used phosphonium based ILs [13,15,26]. In addition, thermal stability is often misleadingly reported to extend up to temperatures of more than 400 ºC.…”

Section: Introductionmentioning

confidence: 99%

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Isoconversional kinetic analysis applied to five phosphonium cation-based ionic liquids

et al. 2017

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Thermal degradation of five phosphonium cation-based ionic liquids ([P 66614 outperforming the other ones in both pyrolytic and oxidising conditions. Although the thermal degradation mechanism is affected by atmospheric conditions, the degradation trend remains practically constant. As the dynamic methodology usually overestimates the long-term thermal stability, an isoconversional methodology is better for predicting the long-term thermal stability of these ionic liquids in order to be used as base oil or additive in lubricants formulation. Finally, the model-free methodology can predict at lower costs the ILs performance in isothermal conditions. Highlights• Weakly coordinating anions provoke good thermal stability of ILs.• • Isoconversional methods are better than dynamic ones for long-term thermal studies.• Activation energy behavior at low conversions is related to a single reaction.• Model-free methodology can predict the ILs performance in isothermal conditions.

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Highly‐fluorinated Triaminocyclopropenium Ionic Liquids

Curnow

Senthooran

2022

Chemistry An Asian Journal

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A series of highly‐fluorinated triaminocyclopropenium salts, with up to six fluorous groups, were prepared and their properties as ionic liquids investigated. Reaction of pentachlorocyclopropane or tetrachlorocyclopropene with bis(2,2,2‐trifluoroethyl)amine, HN(CH2CF3)2, occurs in the presence of a trialkylamine, NR3, to give cations with two fluorinated amino groups, [C3(N(CH2CF3)2)2(NR2)]+ (R=Et, Pr, Bu, Hex), with traces of [C3(N(CH2CF3)2)3]+. Use of appropriate reagent ratios and reaction times and subsequent addition of a dialkylamine, HNR'R”, gives cations with one fluorinated amino group, [C3(N(CH2CF3)2)(NR2)(NR'R”)]+ ((NR2)(NR'R”)=(NBu2)2, (NEt2)(NPr2), (NBu2)(NBuMe)). These cations were isolated as chloride salts and some of these were converted to bistriflamide, dicyanamide and triflate salts to provide ionic liquids. These salts were characterised by thermal (DSC and TGA) measurements and miscibility/solubility properties (determined in a range of solvents). Ionic liquids (ILs) were also characterised by density, viscosity and conductivity measurements where possible. X‐ray diffraction studies of chloride salts showed the formation of fluorous regions and more hydrophilic ionic regions in the solid state.

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Quaternary phosphonium-based ionic liquids: Thermal stability and heat capacity of the liquid phase

Cited by 101 publications

References 55 publications

<strong>SHORT-TERM THERMAL STABILITY OF IONIC LIQUIDS</strong>

<strong>SHORT-TERM THERMAL STABILITY OF IONIC LIQUIDS</strong>

Isoconversional kinetic analysis applied to five phosphonium cation-based ionic liquids

Highly‐fluorinated Triaminocyclopropenium Ionic Liquids

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