Thermal stability of imidazolium-based ionic liquids

Chancelier, Léa; Boyron, Olivier; Gutel, Thibaut; Santini, Catherine C.

doi:10.17721/fujcv4i1p51-64

Cited by 18 publications

(21 citation statements)

References 134 publications

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“…The characteristic degradation temperatures of the different nanocomposites are collected in Table 1. PHBHHx shows a single degradation stage, which is in agreement with what is reported in the literature [33] and starts (T start ) at about 290 • C [34] and shows 10% weight loss (T 10 ) at the maximum rate of weight loss (T peak ) at about 314 and 325 • C, respectively. The degradation likely takes place by means of a random chain scission mechanism, resulting in smaller polymeric segments with COOH terminal groups and crotonic acid as one of the typical by-products [35].…”

Section: Thermal Stabilitysupporting

confidence: 91%

Effect of Graphene Oxide on the Properties of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate)

Díez‐Pascual

2021

Polymers

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The main shortcomings of polyhydroxybutyrate (PHB), which is a biodegradable and biocompatible polymer used for biomedical and food packaging applications, are its low thermal stability, poor impact resistance and lack of antibacterial activity. This issue can be improved by blending with other biodegradable polymers such as polyhydroxyhexanoate to form poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), which is a copolymer with better impact strength and lower melting point. However, PHBHHx shows reduced stiffness than PHB and poorer barrier properties against moisture and gases, which is a drawback for use in the food industry. In this regard, novel biodegradable PHBHHx/graphene oxide (GO) nanocomposites have been prepared via a simple, cheap and environmentally friendly solvent casting method to enhance the mechanical properties and antimicrobial activity. The morphology, mechanical, thermal, barrier and antibacterial properties of the nanocomposites were assessed via several characterization methods to show the enhancement in the biopolymer properties. The stiffness and strength of the biopolymer were enhanced up to 40% and 28%, respectively, related to the strong matrix-nanofiller interfacial adhesion attained via hydrogen bonding interactions. Moreover, the nanocomposites showed superior thermal stability (as far as 40 °C), lower water uptake (up to 70%) and better gas and vapour barrier properties (about 45 and 35% reduction) than neat PHBHHx. They also displayed strong biocide action against Gram positive and Gram negative bacteria. These bio-based nanocomposites with antimicrobial activity offer new perspectives for the replacement of traditional petroleum-based synthetic polymers currently used for food packaging.

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Section: Thermal Stabilitysupporting

confidence: 91%

Effect of Graphene Oxide on the Properties of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate)

Díez‐Pascual

2021

Polymers

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“…This can be attributed due to the presence of van der Waals force and coulombic interactions such as hydrogen bonds between alkyl chains. 54 On similar lines, it has also been found that all ILs fully decomposed in the range of 696–700 °C (refer Figure 10(a)). The DSC analysis of different ILs has been shown in Figure 10 (b) and it can be concluded that IL4 had better heat flow as compared to other ILs.…”

Section: Resultssupporting

confidence: 60%

“…In the view of the industrial application of ILs, the melting point and decomposition temperature have an important role in the thermal stability of the ILs. 54 Thermal stability behaviour of ILs with different alkyl chain length has been shown in Figure 10(a) to (b). According to the findings, the mass loss of ILs has been augmented with an increase in alkyl chain length (refer Figure 10(a)).…”

Section: Resultsmentioning

confidence: 99%

Thermo-physical and tribological characteristics of ionic liquid-based rice bran oil as green cutting fluid

Singh

Sharma

2021

Proceedings of the Institution of Mechanical Engineers, Part J:

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During machining, the cutting fluids play an essential role in cooling and lubrication. In order to reduce the friction forces, the excessive amount of the cutting fluids are generally used. This, in turn, leads to wastage of the cutting fluids which results in a serious impact on the environment, health and cost of production. Therefore, the judicious use of lubricants is the foremost concern in the manufacturing industry. In order to mitigate these drawbacks, various alternatives have been developed in the last decade. In the present paper, ionic liquids have been proved as favourable sustainable alternative additives in the base oil. The effect of alkyl chain length of ionic liquids with base oil on the thermo-physical and tribological characteristics of cutting fluids including viscosity, wettability, anticorrosion behaviour, thermal stability, and coefficient of friction have been analysed. In the present study, pyrrolidinium and hexafluoro-phosphate (PF6) have been used as cation and anion, respectively, with rice bran oil as base oil. The five different ionic liquids have been dispersed in base oil by 1.0 wt%. It has been found that longer alkyl chain length showed the favourable results as compared to the shorter one. Results indicated that ionic liquid based cutting fluid attained ample enhanced thermophysical and tribological properties as compared to the neat rice bran oil. There has been 5.08% and 4.29% improvement in viscosity and thermal conductivity for IL4 + RBO in comparison to neat RBO. In addition, the wettability, coefficient of friction, and wear volume have been reduced by 20.34%, 53.79% and 57.87% correspondingly.

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“…60 In this work, reboiler temperatures were maintained below 135 °C, which is a conservative temperature limit considering the onset of decomposition temperatures for both ILs. 61,62 The [C 2 C 1 im][Tf 2 N] is considered the preferred entrainer since it has the lowest viscosity, the highest thermal stability, and is the most stable in the presence of water at elevated temperatures. 63 The other ionic liquid [C 4 C 1 im][PF 6 ] is also stable at operating temperatures described in this work and in some cases demonstrates a higher selectivity for HFC-32 from ethane-based refrigerants such as HFC-125 and HFC-143a.…”

Section: Introductionmentioning

confidence: 99%

Process Designs for Separating R-410A, R-404A, and R-407C Using Extractive Distillation and Ionic Liquid Entrainers

Finberg

Shiflett

2021

Ind. Eng. Chem. Res.

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Hydrofluorocarbon refrigerants are being phased out over the next two decades due to their high global warming potential. To separate and recycle refrigerants that form azeotropic mixtures, current distillation methods are inadequate and a new technology is required. Extractive distillation using an ionic liquid as the entrainer offers a solution. Vapor liquid equilibria data for refrigerants difluoromethane (HFC-32), chlorodifluoromethane (HCFC-22), pentafluoroethane (HFC-125), 1,1,1-trifluoroethane (HFC-143a), and 1,1,1,2-tetrafluoroethane (HFC-134a) in ionic liquids 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2C1im][Tf2N]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([C4C1im][PF6]) were fit with the Peng–Robinson equation of state to simulate the separation of four azeotropic refrigerant mixtures (R-404A, R-407C, R-410A, and R-410A + HCFC-22) and to develop rate-based and equilibrium models in ASPEN Plus. Process flow diagrams were developed and optimized based on a set of physical and chemical constraints. The goal was to optimize the parameters to achieve refrigerant grade (>99.5 wt %) purity. The ionic liquids were found to be effective entrainers for separating refrigerant mixtures.

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Thermal stability of imidazolium-based ionic liquids

Cited by 18 publications

References 134 publications

Effect of Graphene Oxide on the Properties of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate)

Effect of Graphene Oxide on the Properties of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate)

Thermo-physical and tribological characteristics of ionic liquid-based rice bran oil as green cutting fluid

Process Designs for Separating R-410A, R-404A, and R-407C Using Extractive Distillation and Ionic Liquid Entrainers

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