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The efficient capture of CO 2 from flue gas or directly from the atmosphere is a key subject to mitigate global warming, with several chemical and physical absorption methods previously reported. Through polarizable molecular dynamics (MD) simulations and high-level quantum chemical (QC) calculations, the physical and chemical absorption of CO 2 by ionic liquids based on imidazolium cations bearing oxirane groups was investigated. The ability of the imidazolium group to absorb CO 2 was found to be prevalent in both the tri- and tetraepoxidized imidazolium ionic liquids (ILs) with coordination numbers over 2 for CO 2 within the first solvation shell in both systems. Thermodynamic analysis of the addition of CO 2 to convert epoxy groups to cyclic carbonates also indicated that the overall reaction is exergonic for all systems tested, allowing for chemical absorption of CO 2 to also be favored. The rate-determining step of the chemical absorption involved the initial opening of the epoxy ring through addition of the chloride anion and was seen to vary greatly between the epoxy groups tested. Among the groups tested, the less sterically hindered monoepoxy side of the triepoxidized imidazolium was shown to be uniquely capable of undergoing intramolecular hydrogen bonding and thus lowering the barrier required for the intermediate structure to form during the reaction. Overall, this theoretical investigation highlights the potential for epoxidized imidazolium chloride ionic liquids for simultaneous chemical and physical absorption of CO 2 .

A diepoxy-functionalized 1,2,3-triazolium ionic liquid is synthesized in three steps and used in combination with a poly(propylene glycol) diamine to obtain ion-conducting epoxy-amine networks (EANs). The curing kinetics are followed by Fourier transform infrared spectroscopy, while the physical, mechanical, and ion-conducting properties of the resulting networks are studied by swelling experiments, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical thermal analysis, and broadband dielectric spectroscopy. The curing kinetics and thermomechanical properties of this system are relatively similar to those of conventional DGEBA- (bisphenol A diglycidyl ether)-based EANs with low glass transition temperature (Tg = -44 and -52 °C, respectively) characteristic of rubbery polymer networks. The anhydrous ionic conductivity of the pure network at 30 °C reaches a remarkably high value of 2 × 10(-7) S cm(-1) that could be further increased to 10(-6) S cm(-1) by the addition of 10 wt% LiTFSI., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this study, LIonomers families based on phosphonium ILs have been successfully developed. These LIonomers are designed from the combination of various phosphonium‐based ionic liquids (PhILs) with different counter anions including tetradecyl (trihexyl) phosphonium bis (2,4,4‐trimethylpentyl) phosphinate (P+TMP), tributyl (ethyl) phosphonium diethyl phosphate (P+DEP), trihexyl (tetradecyl) phosphonium chloride (P+Cl) and trihexyl (tetradecyl) phosphonium acetate (P+Ac). Here, the interactions between maleic anhydride groups (MA) of the maleic anhydride‐grafted polypropylene (PPgMA) and PhILs within LIonomers have been investigated by NMR, whose intensity depends on the chemical nature of cation/anion pairs. Then, viscosity in the molten state was considered as a probe of the interaction intensity between polar groups of grafted polypropylenes and the phosphonium cation. The proper one can be tuned from the nature (P+TMP vs. P+Ac vs. P+Cl), from the steric hindrance, that is, relevant to the conformation of PhILs (P+DEP vs. P+TMP / P+Ac / P+Cl), and by MA content, as well as the extent of generated ionic chains from polar groups of matrices as "head" and associated anion/cation pairs. The effect of these generated ionic interactions on crystallization process and mechanical properties had been also investigated by DSC in non‐isothermal conditions, and tensile tests. Depending of the steric hindrance of the phosphonium ILs playing a key role on the interactions with PPgMA chains, an increase of the ductility versus a plasticizing effect can be obtained as function of the targeted applications. [ABSTRACT FROM AUTHOR]

In this work, by combining maleic anhydride-grafted polypropylene (PPgMA) and three different ionic liquids (ILs), i.e., tributyl (ethyl) phosphonium diethyl phosphate (denoted P+DEP), 1-ethyl-3-methylimidazolium diethyl phosphate (denoted EMIM DEP), and 1-ethyl-3-methylimidazolium acetate (denoted EMIM Ac), new ionic PP/IL polymer materials are generated and denoted as LIonomers. The structuration of ILs in LIonomers occurs from a nano/microphase separation process proved by TEM. NMR analyses reveal the existence of ionic–ionic and ionic–dipolar interactions between PPgMA and ILs within LIonomers. The rheological behavior of such IL/polymer combinations interpret the existence of interactions between maleic anhydride group and cation or anion composing the ionic liquid. These interactions can be tuned by the nature of cation (P+DEP vs. EMIM DEP) and anion (EMIM DEP vs. EMIM Ac) but also depend on the IL content. Thermal analyses demonstrate that IL could affect the crystallization process according to different pathways. Thanks to the maleic anhydride/IL interactions, an excellent compromise between stiffness and stretchability is obtained paving the way for processing new polyolefin-based materials. [ABSTRACT FROM AUTHOR]

In the last few years, polymer materials scientists have put a lot of effort into the design of poly­mer-based materials, tailored from the nanometer scale via the introduction of block copolymers, ionomers, or inorganic-rich nano-objects in order to introduce functionalities such as mechanical reinforcement, gas barrier properties, fire retardancy, etc. In the last decade, ionic liquids (ILs) have moved from relative obscurity to something that most chemists are now very aware of. At present, the interest in ILs shows a continuous increase and they are being examined as new components within polymer-based materials for a wide range of applications of advanced materials. The unique set of physico-chemical properties of ILs finely tuned from their chemical structure makes them suitable in numerous applications in polymer science. ILs can be investigated as additives in the design of polymer materials, as novel electrolytes in batteries, as structuration agents of polymer matrices, and as processing aids, plasticizers, and surfactants in the preparation of functional polymers. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, epoxy-networked polymeric materials containing tributyl (ethyl) phosphonium diethyl phosphate (CYPHOS®IL169) and trihexyl (tetradecyl) phosphonium bis 2,4,4-(trimethyl pentyl)-phosphinate (CYPHOS®IL104) were developed from a mixture of epoxy prepolymer (DGEBA) and different amounts of ionic liquids (10-20-30 phr). Then, the effect of the chemical nature of ionic liquids on the final properties of epoxy networks was studied. Thus, the use of phosphonium salts as new additives led to the network with a high conversion of epoxy group (>90%), a high glass transition temperature Tg (>90 °C), adjustable in function of the counteranion and an increase of the storage modulus. In addition, the hydrophobic behavior and the thermal stability of the materials were also investigated by sessile drop method and thermogravimetric analyses. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 3463-3471 [ABSTRACT FROM AUTHOR]

In this work, synthetic layered silicates denoted Somasif ME-100 and Laponite® RD were modified with dialkyl imidazolium and alkyl phosphonium ionic liquids by cationic exchange reaction. In both cases, the phosphonium (P-ME, P-RD) or imidazolium ion (I-ME, I-RD)-treated micas and laponites display an excellent thermal stability compared to commonly used quaternary ammonium salts. To highlight the effect of these ionic liquids, the modified layered silicates were introduced in a high density polyethylene (HDPE). Thus, polyethylene nanocomposites filled with a low amount of nanoparticles (2 wt%) were prepared by twin screw extrusion. Then, transmission electronic microscopy (TEM) analysis has been used to investigate the effect of ILs on the different morphologies of these nanocomposites. In addition, the use or not of compatibilizer such as PEgMA (20% by weight) has been also studied on the mechanical behaviour of these polymer nanocomposites. Even though the thermal stability of polyethylene matrix remains unchanged, a good stiffness-thoughness compromise has been observed. [ABSTRACT FROM AUTHOR]

The use of new building blocks based on phosphonium ionic liquids to develop polymeric materials combining a structuration on the nanoscale with the dramatic water vapour permeability and mechanical properties has been successfully investigated for the first time in a biopolymer matrix. [ABSTRACT FROM AUTHOR]

ABSTRACT Diglycidyl ether of Bisphenol A/Jeffamine D400 system was modified with 2.5 and 5.0 phr of ionic liquids based on imidazolium and phosphonium cations denoted N,N ′-dioctadecyl-imidazolium iodide, or octadecyl-triphenylphosphonium iodide, [OdTPP][I], aiming to develop new networked materials with enhanced performance particularly in terms of mechanical properties and conductivity. The curing behavior was investigated by differential scanning calorimetry, suggesting that the presence of ionic liquids (ILs) accelerates the curing process of the epoxy system. Then, the networked materials were analyzed by dynamic mechanical analysis, and mechanical testing. The presence of the ILs did not affect the glass transition temperature but resulted in a decrease on the storage modulus. By transmission electron microscopy, we have highlighted that the ILs are not miscible inside the epoxy matrix. In fact, a phase separation in nanometric scale has been observed. Measurements of conductivity revealed that the system modified with [OdTPP][I] presented higher dielectric constant and higher electrical conductivity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39834. [ABSTRACT FROM AUTHOR]

Abstract: This work is focused on the tailoring of dispersions of layered silicates, such as MICA SOMASIF (ME-100) within a fluoride matrix (polytetrafluoroethylene) through two strategies: the physicochemical interactions between filler and matrix and the processing of materials. The interactions in these complex systems are modified by new environmentally friendly thermally stable surfactants. The ionic liquids used are based on alkyltriphenyl phosphonium and perfluorinated alkylpyridinium cations. The influences of the cation–anion combination and functionalization were investigated. The use of the supercritical carbon dioxide (ScCO2) as a solvent is relevant to generate structuring within the material based on ionic liquid phase separation. The tunability of ionic liquids and their combination with the supercritical carbon dioxide enables to design materials with optimized thermal and mechanical properties. [Copyright &y& Elsevier]

Abstract: Different ionic liquids based on alkyltriphenylphosphonium and imidazolium-functionalized either with two alkyl chains or with a fluorinated chain have been synthesized and used as interfacial agents for the layered silicates. The effect of the chemical nature of the organic cation on the morphology and the physical properties of the polyvinylidene fluoride (PVDF) nanocomposites has been studied. The influence of ionic liquids on polymorphic crystalline forms, i.e. α and β phases of the polymer matrix was discussed. [Copyright &y& Elsevier]

Abstract: In this work, a new method to prepare fluorinated coatings with mechanical properties enhanced has been developed. Pyridinium, imidazolium, and phosphonium ionic liquids have been synthesized and used as new synthetic building blocks in a polytetrafluoroethylene matrix. The strategy demonstrated using long alkyl chain cations provides an opportunity to prepare nanomaterials with a nanoscale structuration. The design of these new ionic and nanostructured materials is very dependent on the cation–anion combination of ILs. The morphology analyzed by transmission electronic microscopy (TEM) shows that it is clearly tuned by the chemical nature of ILs. The finest structuration leads to a dramatic compromise between stiffness and deformation of material. The small-angle X-Ray scattering (SAXS) shows the evolution of the ionic networks during the mechanical sollicitation. [Copyright &y& Elsevier]

Abstract: Ionic liquids based on alkyltriphenyl phosphonium and dialkyl imidazolium cations with long alkyl chains have been synthesized and used as new surfactants for cationic exchange of layered silicates. The influence of the alkyl chain length and the chemical nature of the conteranion or of the cation on the thermal stability of these new intercalating agents and on imidazolium- (MMT-I) or phosphonium- (MMT-P) modified montmorillonites have been analyzed by thermogravimetric analysis (TGA). Thermoplastic nanocomposites based on these modified montmorillonites with a very low amount of nanofillers (1wt.%) have been processed by melt mixing using a twin screw extruder. The distribution of the clay layers in a high density polyethylene (HDPE) matrix was characterized and finally the mechanical and thermal properties of the corresponding nanocomposites were determined. [ABSTRACT FROM AUTHOR]

Abstract: The use of supercritical CO2 as solvent in the modification of montmorillonite by imidazolium and phosphonium ionic liquids bearing long alkyl chains (C18) known for their excellent thermal stability is described. The objective is to combine the environmentally friendly character of ionic liquids and supercritical carbon dioxide for the organophilic treatment of lamellar silicates. Dialkyl imidazolium and alkyl phosphonium salts were synthesized to be used as new surfactants for cationic exchange of layered silicates. Then, the synthesized phosphonium (MMT-P) or imidazolium (MMT-I) modified montmorillonites, cationically exchanged under supercritical carbon dioxide with or without co-solvent, have been analyzed by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) and compared to montmorillonites treated by conventional cationic exchange. [ABSTRACT FROM AUTHOR]

Abstract: Dialkyl imidazolium and alkyl phosphonium salts were synthesized to be used as new surfactants for cationic exchange of layered silicates, such as montmorillonite (MMT). The synthesized phosphonium (P-MMT) or imidazolium ion (I-MMT)-modified montmorillonites display a dramatically improved thermal degradation with respect to commonly used quaternary ammonium salts. This thermal degradation window can still be shifted toward higher temperatures after washing of modified clays. Two kinds of organic species can be identified onto clay: physically adsorbed species versus chemically adsorbed species. To evidence the impact of these thermally resistant ionic liquids, the modified montmorillonites were introduced in a great commodity polymer, i.e., high-density polyethylene. Thermoplastic nanocomposites with a very low amount of nanofillers were processed in melt by twin screw extrusion. If the thermal stability of polyethylene is slightly increased with only 2wt.% of thermostable made clays, the stiffness–toughness compromise is well improved since a strong increase in modulus is achieved with both thermostable clays without loss of fracture properties. But these mechanical performances are mainly obtained with unwashed thermostable clays because the physically adsorbed organic species onto clay surfaces behave like a compatibilizer that helps both the dispersion into the PE matrix and improves the clay/matrix interface quality. [Copyright &y& Elsevier]

New epoxy-amine networks issue from epoxydized imidazolium ionic liquid monomers (ILMs) and isophorone diamine (IPD) were modified for the first time by incorporating unmodified trisilanol phenyl POSS® (POSS®Ph-triol) and two ionic liquid-modified POSS®Ph (IL-g-POSS®Ph) having chloride (Cl−) and bis-trifluoromethanesulfonimidate (NTf2−) counter anions. Then, 5 wt.% of unmodified and IL-modified POSS®Ph were introduced in order to develop new solid electrolytes. First, a homogeneous dispersion of the POSS®Ph aggregates (diameters from 80 to 400 nm) into epoxy networks was observed. As a consequence, ILM/IPD networks with glass transition temperatures between 45 and 71 °C combined with an enhancement of the thermal stability (>380 °C) were prepared. Moreover, a significant increase of the hydrophobic character and high oil repellency of the network surfaces were obtained by using IL-g-POSS®Ph (19–20 mJ.m−2), opening up promising prospects for surface coating applications. Finally, these new epoxy networks exhibited outstanding high ionic conductivities (from 3.4 × 10−8 to 6.8 × 10−2 S.m−1) combined with an increase in permitivity. [ABSTRACT FROM AUTHOR]

Recently, a new generation of polymerised ionic liquids with high thermal stability and good mechanical performances has been designed through novel and versatile cycloaliphatic epoxy-functionalised ionic liquids (CEILs). From these first promising results and unexplored chemical structures in terms of final properties of the PILs, a computational approach based on molecular dynamics simulations has been developed to generate polymer models and predict the thermo–mechanical properties (e.g., glass transition temperature and Young's modulus) of experimentally investigated CEILs for producing multi-functional polymer materials. Here, a completely reproducible and reliable computational protocol is provided to design, test and tune poly(ionic liquids) based on epoxidised ionic liquid monomers for future multi-functional thermoset polymers. [ABSTRACT FROM AUTHOR]

Phosphonium based ionic liquids (ILs) have been previously shown as a new emerging class of initiator of epoxy prepolymers. The present study aims at investigating the influence of ILs on the dielectric behaviour of epoxy-IL systems by dielectric spectroscopy. Here, the content of IL incorporated in the epoxy prepolymer has a significant impact on the final properties of the polymer networks displaying a high glass transition temperature (Tg > 160 °C). The excess of IL (>10 phr) acts as a plasticizer agent decreasing the Tg and leading to the formation of heterogeneities. Moreover, the study of α and β conventional relaxation modes by dielectric spectroscopy highlighted an increase of chain mobility due to IL excess. A ω relaxation mode has been noticed with the addition of high content of IL, probably relating to heterogeneities of the network. Unlike the most of polymer systems, the study of the DC conductivity by the application of an Arrhenius law demonstrated a thermal activation mechanism, independent from the free volume and the glass transition phenomenon. A discussion on the identification of charge carriers has been finally proposed. [Display omitted] • Epoxy-phosphonium/phosphinate IL systems were processed leading to high crosslink density networks. • Structure-property relationship of epoxy-IL network was established trough molecular mobility characterizations. • Electrical conductivity of epoxy networks can be tuned leading to interesting properties for insulation applications. [ABSTRACT FROM AUTHOR]

The use of ionic liquids as functional building blocks based on pyridinium, imidazolium and phosphonium cations to achieve materials combining a structuration at nanoscale with the dramatic mechanical properties of the resulting ionomers has been successfully demonstrated for the first time in a fluorinated matrix. [ABSTRACT FROM AUTHOR]

Here, ionic liquids (ILs) based on imidazolium and ammonium cations were used as modifying agents for poly(methyl methacrylate) (PMMA) by extrusion. The effects of the chemical nature of the cation and/or counter anion on the resulting properties of IL-modified PMMA blends were analyzed. It was found that the use of low amounts of ILs (2 wt.%) improved the thermal stability. A plasticizing effect of ILs is evidenced by a decrease in glass transition temperature Tg of the modified PMMA, allowing to get large strains at break (i.e., up to 280% or 400%) compared to neat PMMA. The deformation and fracture mechanisms of PMMA under uniaxial tensile stress (i.e., crazing) reveal that the presence of IL delayed the strain during the initiation step of crazing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Design of new Self-healing epoxy composites based on poly(urea- formaldehyde) microcapsules containing epoxy prepolymer. • Phosphonium ionic liquid as initiator for the encapsuled epoxy prepolymer. • Effect of ionic liquids in the curing process of epoxy-amine networks. • Effect of the poly(urea- formaldehyde) microcapsules on the thermal and mechanical performances. Extrinsic self-healing mechanism is an original route for achieving self-healing polymer materials. The use of microencapsulated diepoxized monomer as healing agent for the design of self-healable epoxy-amine networks is thus a promising strategy limiting only by the decomposition temperature of the curing agent. Therefore, this work put forward the idea of a single microcapsule system by using free ionic liquid (IL) as an initiator of the healing agent, which can be applied for epoxy-amine thermosets requiring higher curing temperatures. Thus, the synthesis of epoxy-amine-ionic liquid networks containing microcapsules was firstly investigated. Then, the morphology as well as the physical properties of these networks, i.e. the thermal stability and mechanical performances were also determined. Finally, the self-healing ability was highlighted by using over than 10 wt% of EP@PUF microcapsules. [ABSTRACT FROM AUTHOR]

In this work, new gelled electrolytes were prepared based on a mixture containing phosphonium ionic liquid (IL) composed of trihexyl(tetradecyl)phosphonium cation combined with bis(trifluoromethane)sulfonimide [TFSI] counter anions and lithium salt, confined in a host network made from an epoxy prepolymer and amine hardener. We have demonstrated that the addition of electrolyte plays a key role on the kinetics of polymerization but also on the final properties of epoxy networks, especially thermal, thermo-mechanical, transport, and electrochemical properties. Thus, polymer electrolytes with excellent thermal stability (>300 °C) combined with good thermo-mechanical properties have been prepared. In addition, an ionic conductivity of 0.13 Ms·cm−1 at 100 °C was reached. Its electrochemical stability was 3.95 V vs. Li0/Li+ and the assembled cell consisting in Li|LiFePO4 exhibited stable cycle properties even after 30 cycles. These results highlight a promising gelled electrolyte for future lithium ion batteries. [ABSTRACT FROM AUTHOR]

• Addition of phosphonium Ionic Liquid interestingly modifies mechanical properties of PBAT. • Depending on the counter anion, the ionic liquid is miscible or not with PBAT. • AFM nanomechanical mappings highlights the complex structurating mechanism. • Dielectric spectroscopy helps to identify rigid and mobile amorphous phases. The influence of the addition in small amounts (2 wt%) of two phosphonium–based ionic liquids (ILs) on the nanostructuration and mechanical properties of a poly(butylene-adipate- co -terephtalate) (PBAT) matrix was investigated using complementary approaches. Dielectric spectroscopy and nanomechanical characterizations using atomic force microscopy (PeakForce QNM mode, Bruker) were used along X-ray diffraction, differential scanning calorimetry and dynamic mechanical analysis to explain the mechanical (tensile) properties of each system. The semicrystalline matrix was found to have a spherulitic structure, with crystalline lamellae composed of butylene terephtalate units. In one case, the addition of an immiscible phosphonium-phosphinate ionic liquid (il-TMP) to the matrix, inducing a 33% increase of the strain at break, was found via AFM to induce a nodular microstructure with dissipative effects and smooth nodule-matrix interphases. In the other case, a phosphonium-chloride ionic liquid (il-Cl), being miscible in the amorphous phases, increases the chain mobility of the mobile amorphous fraction (MAF) consisting of free polymer chains, while it hinders the relaxation, thus chain movements, of the confined rigid amorphous fraction (RAF). This double effect induced a moderate macroscopic Young's modulus drop (less than −20%) with a +60% increase of the strain at break, and no significant influence on thermal properties. AFM in situ mechanical measurements, along with dielectric spectroscopy, allowed to propose complete mechanisms for the ILs-matrix interactions, highlighting the potential of such additives for the tuning of the properties of polymers. [ABSTRACT FROM AUTHOR]

Ionic liquids based on tetraalkylphosphonium salts combined with different anions (phosphinate versus trifluoromethylsulfonylimide) have been used as new compatibilizers of polymer blends. To highlight the effect of thermostable ionic liquids, a very low amount of ILs (1-10 wt%) have been introduced within a PP/PA blend (80/20) and the polymer blends have been processed in melt by twin-screw extrusion. Transmission electron microscopy (TEM) analysis has been used to investigate the influence of ILs on the different morphologies of these binary blends. In addition to having improved thermal stability, an excellent stiffness-toughness compromise has been obtained (+1400%). [ABSTRACT FROM AUTHOR]

The molecular design of nanostructured epoxy-amine networks by using IL-grafted POSS as inorganic-organic nano-building blocks. In this work, two polyhedral oligomeric silsesquioxane-supported imidazolium ionic liquid have been successfully synthesized and used as organic-inorganic hybrid nano-objects in order to design nanostructured epoxy-amine networks. In fact, two partially condensed POSS have been covalently grafted with an ionic liquid-functionalized silane. The thermal properties of the ionic liquid (IL)-modified POSS have highlighted a significant enhancement of the thermal stability (400 vs 300 °C). Then, these hybrid organic-inorganic nano-objects (5 wt%) have been incorporated into a conventional epoxy prepolymer (diglycidyl ether of bisphenol A) which was copolymerized with the isophorone diamine in order to prepare nanostructured networks. Thus, an excellent dispersion of the IL-functionalized POSS was obtained in the thermosetting networks, characterized by the formation of spherical or ellipsoïdal inorganic-rich nanoparticles with nanoscale sizes (10–80 nm). [ABSTRACT FROM AUTHOR]

Graphical abstract Influence of cations and anions on the formation of gamma polar phase in polyvinylidene fluoride. Highlights • Polymer/Ionic liquids system can be treated as a ternary system. • The effect of the chemical nature of the cation and the anion may interfere on the crystalline phase formation of the PVDF polymer. • The acidity Brønsted difference of the ionic liquids result in different polarities in the main polymer chain. • A nanoestruturação por ILS promove RAF e MAF. • The existence of ILs in the RAF acts as an obstacle for the growth of larger structures. Abstract The ability of different microstructures from ionic liquids (ILs) governed by anions and cations has been a source of curiosity for composite systems. In this present study, the structural behavior of polyvinylidene fluoride (PVDF) mixed with phosphonium- and imidazolium-based ionic liquids (1 wt%) combined with different counter anions was investigated. The effect of the chemical nature of the cation and the anion on the resulting polar crystals was evaluated. Thus, the formation of polar phase after IL incorporation was highlighted with morphologic observation of spherulites of low-birefringence using polarizing optical (POM) and atomic force microscopies (AFM), and their crystalline structures were confirmed by infrared spectroscopy (FTIR) and Wide-angle X-ray diffraction (WAXS). However, the enhancement of polar γ-phase crystallization was mainly observed in presence of phosphonium-based ILs suggesting that the nanostructuration mechanism were amply dependent on the interacting abilities of ILs in PVDF matrix. In addition, we have also demonstrated that the presence of ILs within the crystalline lamellae, characterized by SAXS and DMA, oriented the chains allowing the formation of rigid amorphous fraction (RAF). For this reason, we proposed that the depression of spherulites size was due to the existence of ILs in the RAF acting as obstacle for the growth of larger structures. Finally, these different changes in the microscopic level structure bestowed a rather unique property which modified the mechanical performance of the polymer materials, especially the ability to sustain large deformation. [ABSTRACT FROM AUTHOR]

Aircraft, automotive industries and the increasing numbers of wind turbine blade lead to a huge amount of carbon fiber reinforced polymers requiring to be recycled and/or reused in a closed loop supply chain or circularity of materials. Herein, we have designed and synthesized a tetra-epoxidized imidazolium ionic liquid (Tetra-IL) monomer containing ester-cleavable groups. This monomer was incorporated as a molecular brick platform into conventional epoxy-amine networks in order to tailor the physical properties as well as the end-of-life of the resulting networks. Thus, the introduction of only 10% of IL-based comonomers significantly reduced the gel time by 85% opening perspectives in the field of fast-cure epoxy resins. Overall, all the networks designed in this work presented high thermal stability (>350 °C), higher T g included between 180 and 230 °C combined with hydrophobic behavior. Increasing the amount of IL monomer in the networks improved the homogeneity of thermosets and wettability of the epoxy resins with the carbon fibers (CF). Most importantly, the use of Tetra-IL led to the development of degradable networks under mild conditions within a brief timeframe (4.5 h) and allowing to recover the carbon fibers. In summary, this study highlighted the great potential of IL-based comonomers as molecular brick into conventional epoxy thermosets as a promising strategy to tailor the physical properties versus sustainability/degradability for the development of high-performance thermosets and composites. [Display omitted] [ABSTRACT FROM AUTHOR]

Various amounts of a phosphonium ionic liquid (IL169) were used as curing agents as well as flame retardants of epoxy prepolymer in order to prepare epoxy networks with improved fire properties. The flame retardancy of these resins was investigated using thermogravimetric analysis (TGA), pyrolysis-combustion flow calorimetry (PCFC) and cone calorimetry. Phosphonium ionic liquid significantly reduced flammability without further addition of flame retardants due to the high amount of phosphorus (up to 3.69 wt%). The Peak of heat release rate decreases from 1099 kW/m 2 to 300 kW/m 2 in cone calorimeter at 35 kW/m 2 when incorporating 30 phr of IL169. Phosphorus modifies pyrolysis pathway, promotes charring and may act as flame inhibitor. The char layer protects the underlying polymer, leading to a high unburnt polymeric fraction. Char properties were studied using PCFC, Raman spectroscopy and X-ray tomography. Phosphorus improved the graphitization of the char and its thermo-oxidative stability. [ABSTRACT FROM AUTHOR]

A fundamental understanding of theversatile and tunable nanostructuration effect of two phosphoniumionic liquids (ILs), denoted octadecyltriphenylphosphonium iodide(IL-C18) and tributyl(methyl)phosphonium methylsulfate (IL-108),on a semicrystalline fluorinated copolymer poly(vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-CTFE)) was elaborated.This research suggests that the nanostructuration mechanism is verydependent on the diffusion and interacting abilities of ILs in matrix,which are determined by the chemical structures of ILs. Both ILs appearto diffuse and regularly assemble in the rigid amorphous fraction(RAF) of P(VDF-CTFE) between crystalline lamellae thanks to the “template”confinement effect of 2D structure. The assembled structure showsa gradually regular 1D to 2D geometric evolution with increasing theILs amount revealed by Porod exponents in SANS analyses. Simultaneously,these regularly assembled ILs in the RAF also act as “template”to efficiently induce a complete transition of nonpolar α-phaseto polar γ- and/or β-phase with only a tiny amount ofILs (from 2 wt %) (by XRD and FTIR). Moreover, the crystallizationdisplays a depression behavior with reduced Tc, Tm, crystallinity (by DSC),and crystallite size (by SANS) due to the existence of ILs in theRAF seen as obstacle for the regular chain-folding and the dipolarinteraction with P(VDF-CTFE). We propose that the synergistic influenceof mutual “templates” endues phosphonium ILs a versatilenanostructuration on the fluorinated matrix. Moreover, this versatilenanostructuration effect can be easily tuned by tailoring the chemicalstructures of ILs. The difference in the chemical structures of ILsendows them different diffusion rates upon crystallization from solutionfor preparing resulting blend films and strengths of dipolar interactionwith P(VDF-CTFE), consequently affecting their dispersion state inthe matrix to reside in the RAF with different extents and interactingabilities (confirmed by DEA and DMA). Thus, IL-108 with faster migrationrate and stronger dipolar interaction than IL-C18 (due to the smallersteric hindrance and extra polar groups in the cation/anion combinationof the IL structure) locates in the RAF much more to induce more trans-configuration (β-phase), more homogeneous dispersionmorphology, and higher depression of crystallization. [ABSTRACT FROM AUTHOR]

Due to their outstanding properties such as high optical transparency, high electrical resistance, high thermal insulation, good thermo-mechanical properties, and dimensional stability, epoxy networks play a key role in the world of thermosetting polymers. In fact, they are widely used in Industry as adhesives, paints and coatings, electrical and electronics applications as well as composite matrices for automotive and aerospace applications. Epoxy networks are issued from epoxy prepolymers composed of two to four oxirane rings able to undergo a polyaddition polymerizations with hardeners (amines, phenols, isocyanates, or acids) or a chain homopolymerization reactions in the presence of initiators such as tertiary amines, imidazoles, or ammonium salts. However, the innovations in this area have reached certain technological limits. Very recently, ionic liquids have shown their potential to be used as new initiators or functional building blocks of epoxy prepolymers and as a novel generation of epoxidized ionic liquid monomers. Thus, a new and innovative pathway has emerged producing a new generation of epoxy thermosets issue from ionic liquids by the concept of 'function through structural design' leading to unprecedented improvements in their physical properties. In fact, epoxy networks can be tuned with glass transition temperatures included from -40 to 170°C depending of the targeted applications. Thus, the polymer/ionic liquid synergy leads to the design and development of new dedicated (multi)functional thermosetting materials with improved properties such as ionic conductivity, chemical and thermal stability, fire retardancy, water barrier properties and mechanical performances. The aim of this review is to point out the potential of this novel class of ionic thermoset materials in the field of epoxy thermosets. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] Synthesis of new fluorinated ionic liquids. [•] Use of ionic liquids as additives for porous materials. [•] Green process for preparing foams. [ABSTRACT FROM AUTHOR]

Abstract: Ionic liquids based on tetraalkylphosphonium salts combined with different anions (decanoate and dodecylsulfonate) have been used as intercalating agents of layered double hydroxides (LDHs) by ion exchange. The synthesized phosphonium-treated LDHs display a dramatically improved thermal degradation and a significant increase in the interlayer distance as confirmed by thermogravimetric analysis (TGA) and X-ray Diffraction (XRD), respectively. To highlight the effect of thermostable ionic liquids, a very low amount of LDHs has been introduced within a polylactide (PLA) matrix and PLA/LDHs nanocomposites have been processed in melt by twin-screw extrusion. Then, transmission electron microscopy (TEM) analysis has been used to investigate the influence of ILs on the different morphologies of these nanocomposites. Even though the thermal stability of PLA matrix decreased, an excellent stiffness–toughness compromise has been obtained. [Copyright &y& Elsevier]

Designing innovative multi-functional thermoset polymers represents a major challenge in materials science. In this work, two novel polyhedral imidazolium ionic liquid supported on oligomeric silsesquioxane nanocages having chloride (Cl−) and bistrifluoromethanesulfonimidate (NTf 2 -) counter anions have been synthesized. These ionic nano-objects were used to nanostructure a model epoxy network. Hence, networks displaying a homogeneous nanoscale morphology were obtained by introducing 5 wt % of such organic-inorganic (O/I) silicon-oxo clusters functionalized with ionic liquids. The obtained ionic hybrid O/I epoxy-amine networks display an excellent thermal stability (>400 °C) compared to their neat counterparts, as well as a pronounced hydrophobic character (23 mJ m−2) and good mechanical performances. Moreover, these O/I nanostructured networks demonstrate an improved fire resistance according to pyrolysis-combustion flow calorimetry (PCFC) and cone calorimetry analyses. In fact, the use of low amounts of imidazolium ionic liquid-modified polyhedral oligomeric silsesquioxanes induce a significant decrease of heat release rate (about 55%), as well as a retardation of the ignition time (close to 29%) compared to the neat epoxy-amine network. [Display omitted] • Design of New Ionic Liquid-Grafted Metal-Oxo Nanoclusters. • Synergistic effect of POSS®Ph nanoclusters combined to imidazolium ionic liquids. • Hybrid O/I epoxy networks with higher thermal stability and mechanical performances. • Huge potential for fire retardancy of IL-grafted POSS®Ph modified epoxies. [ABSTRACT FROM AUTHOR]

In this paper, the synergistic use of polyetherimide (PEI) and a phosphonium-based ionic liquid (IL) as multifunctional agents in epoxy networks is evidenced. Indeed, such a combination leads to tailor both morphology and interphase and acts as polymerization initiator. The influence of the PEI content (5, 10, 15, and 20 phr) on the morphology and final properties has been investigated and compared with the ones of the conventional epoxy/amine-thermoplastic networks. According to the complex interphase generated from the thermoplastic-ILcombination, a more pronounced hydrophobic behavior combined with an improved thermal stability were obtained for the epoxy-PEI-IL hybrid networks without degradation of the initial thermoset fracture toughness. Besides, due to the presence of such IL-rich interphase between thermoplastic phase and the epoxy, a shape memory behavior was highlighted for the first time for such polymer blends which can make them very promising materials for applications requiring multifunctionality. Shape memory behavior of novel thermoset/thermoplastic hybrid materials based on ionic liquid. Image 1 • Thermoset/thermoplastic as novel functional polymer materials. • PEI/IL-cured epoxy blends with shape memory behavior. • Epoxy networks with higher thermal stability and hydrophobic behavior. • Ionic Liquid as initiator of polymerization and dissolution agent of thermoplastic. [ABSTRACT FROM AUTHOR]