International audienceTwo series of 1,2,3-triazolium chiral ionic liquid (CIL) stereoisomers are synthesized from isosorbide by combining the robust attributes of the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), alkylation of the resulting 1,2,3-triazoles by methyl iodide and further anion metathesis with different fluorinated salts. These novel biosourced CILs are characterized in details by H-1 and C-13 NMR spectroscopy, high-resolution mass spectrometry (ESI-HRMS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS). The effect of stereochemistry on their physical, thermal and ion conducting properties is discussed. Markedly, it is demonstrated for the first time that stereochemistry can drastically influence ionic conductivity by several orders of magnitude
New biosourced unprotected diols were prepared by acylation reaction of aminoalcohol based on 1,4:3,6-dianhydrosorbitol (Isosorbide Is) with several aliphatic and aromatic diacyl chlorides (sebacoyl, adipoyl, and terephthaloyl). Optimization of reaction conditions (solvent, base nature, and addition mode) has been investigated with protected alcohols. The use of hindered bases was needful to ensure the selectivity of the addition reaction when starting from unprotected aminoalcohol, and selectively led to bis amides products with good yields. 1D and 2D NMR techniques were used to ascertain the structures of the unprecedented monomers. These novel building blocks were successfully polymerized using succinic and terephthalic spacers and studied by NMR and DSC techniques.
Polycaprolactones are obtained via ring opening polymerization of ε‐caprolactone in catalyst‐free condition. The polymerization is initiated in bulk, using isosorbide‐based amino‐alcohol as a biosourced initiator. The ratio of initiator to ε‐caprolactone, as well as to temperature, is optimized in order to tune the hydroxyl number (Nr. OH) and the average molecular weight of the polymers. In addition, these biocompatible polyesters are used as soft‐block to prepare thermoplastic poly(esterurethane)s elastomers via a simple one‐pot catalyst‐free polymerization. The successful synthesis of poly(esterurethane)s is confirmed by Fourier transform‐infrared spectroscopy, and the thermal properties are studied by differential scanning calorimetry. These novel materials exhibit glass transition temperatures ranging from 7 to 38 °C. The biodegradability of these elastomers is evaluated by enzymatic degradation tests performed at rt in phosphate buffer solution (pH ≈ 7.4). The mass loss of polymer films is around 3% after 4 weeks. Scan electron as well as atomic force microscopies are used to show the degradation patterns.
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