1,3,4‐Trisubstituted 1,2,3‐triazolium salts having either aliphatic or benzylic substituents at t... more 1,3,4‐Trisubstituted 1,2,3‐triazolium salts having either aliphatic or benzylic substituents at the N‐1 and N‐3 positions were synthesized in two steps involving: i) copper(I) catalyzed azide‐alkyne 1,3‐dipolar cycloaddition (CuAAC), and ii)N‐alkylation of the 1,2,3‐triazole intermediates. Trans‐N‐alkylation reactions in bulk and in the presence of excess methyl iodide were monitored by 1H NMR spectroscopy for each 1,2,3‐triazolium molecular model. By assigning the different formed species and their respective evolution with time, it was possible to conclude that trans‐N‐alkylation exchange reactions are significantly faster for benzylic substituents than for aliphatic ones. Furthermore, the exchange reactions are noticeably faster at the N‐3 position than at the N‐1 position most likely due to the steric hindrance induced by the neighboring C‐4 substituent. The kinetics of trans‐N‐alkylation reactions are thus influenced by both the chemical nature of the N‐1 and N‐3 substituents a...
The introduction is a brief review of the characteristics desired for heat-resistant composite ma... more The introduction is a brief review of the characteristics desired for heat-resistant composite matrices, and the two possible approaches based on linear polymers and telechelic oligomers that can be cross-linked during use. Special attention is paid to cross-linkable oligomers, whose use currently poses fewer problems. The different structures in question, i.e. bismaleimides, bismaleimides (modified by cyanates or epoxies), bisnadimides, acetylene and propargylic compounds, are discussed in terms of chemistry (stability of oligomers, mode of polymerization, aging) and mechanical properties (ductility). Several solutions little used at the present time (semi-interpenetrated networks, molecular composites, polymerizable molecular assemblies, hyper branched oligomers and liquid crystal monomers, etc.) are discussed in terms of the future. There may be technical solutions for use up to 300°C, but industrial development is far from being resolved because of, among other things, the small...
New ethylenic monomers based on 1,4:3,6-dianhydrohexitols and 5-bromo-2-furaldehyde were prepared... more New ethylenic monomers based on 1,4:3,6-dianhydrohexitols and 5-bromo-2-furaldehyde were prepared by a metal free synthesis of furannyl-isosorbide and isomannide derivatives. The monomers were obtained with high yields. The polymerization of the unsaturated monomer using 2,2’-azobisisobutyronitrile as catalyst provides the resulting polymethacrylate benzyl isosorbide with high molecular weight. The bio-based monomers and polymer were charactherized by several analitycal methods such as 1H NMR, 13C NMR and FTIR spectroscopy. Thermal properties of the polymer were investigated by means of differential scanning calorimetry (DSC) and molecular weights by SEC measurements.
Thumbnail image of graphical abstract A new class of poly(ether ketone)s (PEKs) is prepared by po... more Thumbnail image of graphical abstract A new class of poly(ether ketone)s (PEKs) is prepared by polycondensation of various diols produced from biomass and various difluoro aromatics. After optimization of the reaction conditions, polycondensation of isosorbide and 4,4′-difluorodiphenylketone (2a) gives PEK1 with a high yield, moderate viscosity (0.31 dL g−1), and a glass-transition temperature (Tg) of 170 °C. The optimum conditions are applied to the synthesis of a series of PEKs (PEK 2-9) from difluoro agents and sugar diols. The polycondensation of isomannide (1b) with 1,4-di(p-fluorobenzoyl)benzene (2b) gives the best results with an inherent viscosity of 0.52 dL g−1 and the mass spectrum shows an abundance of cyclic structures. Similar conditions are used for the preparation of high-molar-mass copoly(ether ketone)s from a stoechiometric mixture of isosorbide/bisphenol-A.
In this work, two fluorinated poly(1,2,3-triazolium ionic liquid)s (PTILs) are accessed in two st... more In this work, two fluorinated poly(1,2,3-triazolium ionic liquid)s (PTILs) are accessed in two steps by copper(I)-catalyzed azide–alkyne cycloaddition AA + BB polyaddition between an α,ω-dialkyne-perfluoroether and either 1,12-dodecyl-diazide or α,ω-diazido-tetra(ethylene glycol), followed by N-alkylation of the resulting poly(1,2,3-triazole)s (PTs) by N-methyl bis(trifluoromethylsulfonyl)imide. The structure/properties correlations of PTILs and their PT intermediates are discussed based on solubility, 1H, 13C and 19F NMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and broadband dielectric spectroscopy. Dodecyl- and tetra(ethylene glycol)-based PTILs exhibit glass transition temperatures of − 38 and − 29 °C, temperatures at 10% weight loss of ca. 340 °C and anhydrous ionic conductivities at 30 °C of 1.2 × 10−5 and 8.4 × 10−6 S cm−1, respectively. The impact of different lithium salts (i.e. LiSO3CF3, LiTFSI, and LiClO4,) on ionic conductivity of the t...
La polycondensation de la dibromo-2,6 pyridine avec le sulfure de sodium et le sel dipotassique d... more La polycondensation de la dibromo-2,6 pyridine avec le sulfure de sodium et le sel dipotassique du dimercapto-2,5 thiadiazole-1,3,4 a ete effectuee dans des conditions de catalyse par transfert de phase solide-liquide. Des conditions operatoires permettant de preparer des polythioethers bien definis possedant des groupements brome a chaque extremite ont ete mises au point. La formation d'un trimere cyclique a ete mise en evidence dans certains cas. Ces composes ont ete caracterises par analyse elementaire, spectroscopie ir, rmn du proton et du carbone 13, chromatographie par exclusion sterique et analyse calorimetrique differentielle. L'influence de divers facteurs (solvant, nature et concentration du catalyseur) sur le rendement et la masse molaire des polythioethers a ete examinee. Les bromes terminaux ont ete ensuite substitues par des groupements acetyleniques, en utilisant le systeme catalytique pdc#1#2(p(c#6h#5)#3)#2, cui et p(c#6h#5)#3. Le rendement de la reaction de ...
1,3,4‐Trisubstituted 1,2,3‐triazolium salts having either aliphatic or benzylic substituents at t... more 1,3,4‐Trisubstituted 1,2,3‐triazolium salts having either aliphatic or benzylic substituents at the N‐1 and N‐3 positions were synthesized in two steps involving: i) copper(I) catalyzed azide‐alkyne 1,3‐dipolar cycloaddition (CuAAC), and ii)N‐alkylation of the 1,2,3‐triazole intermediates. Trans‐N‐alkylation reactions in bulk and in the presence of excess methyl iodide were monitored by 1H NMR spectroscopy for each 1,2,3‐triazolium molecular model. By assigning the different formed species and their respective evolution with time, it was possible to conclude that trans‐N‐alkylation exchange reactions are significantly faster for benzylic substituents than for aliphatic ones. Furthermore, the exchange reactions are noticeably faster at the N‐3 position than at the N‐1 position most likely due to the steric hindrance induced by the neighboring C‐4 substituent. The kinetics of trans‐N‐alkylation reactions are thus influenced by both the chemical nature of the N‐1 and N‐3 substituents a...
The introduction is a brief review of the characteristics desired for heat-resistant composite ma... more The introduction is a brief review of the characteristics desired for heat-resistant composite matrices, and the two possible approaches based on linear polymers and telechelic oligomers that can be cross-linked during use. Special attention is paid to cross-linkable oligomers, whose use currently poses fewer problems. The different structures in question, i.e. bismaleimides, bismaleimides (modified by cyanates or epoxies), bisnadimides, acetylene and propargylic compounds, are discussed in terms of chemistry (stability of oligomers, mode of polymerization, aging) and mechanical properties (ductility). Several solutions little used at the present time (semi-interpenetrated networks, molecular composites, polymerizable molecular assemblies, hyper branched oligomers and liquid crystal monomers, etc.) are discussed in terms of the future. There may be technical solutions for use up to 300°C, but industrial development is far from being resolved because of, among other things, the small...
New ethylenic monomers based on 1,4:3,6-dianhydrohexitols and 5-bromo-2-furaldehyde were prepared... more New ethylenic monomers based on 1,4:3,6-dianhydrohexitols and 5-bromo-2-furaldehyde were prepared by a metal free synthesis of furannyl-isosorbide and isomannide derivatives. The monomers were obtained with high yields. The polymerization of the unsaturated monomer using 2,2’-azobisisobutyronitrile as catalyst provides the resulting polymethacrylate benzyl isosorbide with high molecular weight. The bio-based monomers and polymer were charactherized by several analitycal methods such as 1H NMR, 13C NMR and FTIR spectroscopy. Thermal properties of the polymer were investigated by means of differential scanning calorimetry (DSC) and molecular weights by SEC measurements.
Thumbnail image of graphical abstract A new class of poly(ether ketone)s (PEKs) is prepared by po... more Thumbnail image of graphical abstract A new class of poly(ether ketone)s (PEKs) is prepared by polycondensation of various diols produced from biomass and various difluoro aromatics. After optimization of the reaction conditions, polycondensation of isosorbide and 4,4′-difluorodiphenylketone (2a) gives PEK1 with a high yield, moderate viscosity (0.31 dL g−1), and a glass-transition temperature (Tg) of 170 °C. The optimum conditions are applied to the synthesis of a series of PEKs (PEK 2-9) from difluoro agents and sugar diols. The polycondensation of isomannide (1b) with 1,4-di(p-fluorobenzoyl)benzene (2b) gives the best results with an inherent viscosity of 0.52 dL g−1 and the mass spectrum shows an abundance of cyclic structures. Similar conditions are used for the preparation of high-molar-mass copoly(ether ketone)s from a stoechiometric mixture of isosorbide/bisphenol-A.
In this work, two fluorinated poly(1,2,3-triazolium ionic liquid)s (PTILs) are accessed in two st... more In this work, two fluorinated poly(1,2,3-triazolium ionic liquid)s (PTILs) are accessed in two steps by copper(I)-catalyzed azide–alkyne cycloaddition AA + BB polyaddition between an α,ω-dialkyne-perfluoroether and either 1,12-dodecyl-diazide or α,ω-diazido-tetra(ethylene glycol), followed by N-alkylation of the resulting poly(1,2,3-triazole)s (PTs) by N-methyl bis(trifluoromethylsulfonyl)imide. The structure/properties correlations of PTILs and their PT intermediates are discussed based on solubility, 1H, 13C and 19F NMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and broadband dielectric spectroscopy. Dodecyl- and tetra(ethylene glycol)-based PTILs exhibit glass transition temperatures of − 38 and − 29 °C, temperatures at 10% weight loss of ca. 340 °C and anhydrous ionic conductivities at 30 °C of 1.2 × 10−5 and 8.4 × 10−6 S cm−1, respectively. The impact of different lithium salts (i.e. LiSO3CF3, LiTFSI, and LiClO4,) on ionic conductivity of the t...
La polycondensation de la dibromo-2,6 pyridine avec le sulfure de sodium et le sel dipotassique d... more La polycondensation de la dibromo-2,6 pyridine avec le sulfure de sodium et le sel dipotassique du dimercapto-2,5 thiadiazole-1,3,4 a ete effectuee dans des conditions de catalyse par transfert de phase solide-liquide. Des conditions operatoires permettant de preparer des polythioethers bien definis possedant des groupements brome a chaque extremite ont ete mises au point. La formation d'un trimere cyclique a ete mise en evidence dans certains cas. Ces composes ont ete caracterises par analyse elementaire, spectroscopie ir, rmn du proton et du carbone 13, chromatographie par exclusion sterique et analyse calorimetrique differentielle. L'influence de divers facteurs (solvant, nature et concentration du catalyseur) sur le rendement et la masse molaire des polythioethers a ete examinee. Les bromes terminaux ont ete ensuite substitues par des groupements acetyleniques, en utilisant le systeme catalytique pdc#1#2(p(c#6h#5)#3)#2, cui et p(c#6h#5)#3. Le rendement de la reaction de ...
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