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The development of highly active and selective heterogeneous-based catalysts with tailorable properties is not only a fundamental challenge, but is also crucial in the context of energy savings and sustainable chemistry. Here, we show that ruthenium nanoparticles (RuNPs) stabilised with simple polymerised ionic liquids (PILs) based on

The influence of dispersity in the molecular weight distributions in the core forming block for block copolymer (BCP) self-assembly is analyzed via an automated flow synthesis approach.

We integrate continuous flow organocatalysed ring-opening polymerisation with a core-grafting strategy to rapidly and readily prepare multifunctional, processable polyesters. Their potential use in materials applications is subsequently highlighted.

Commercially available lipase fromPseudomonas stutzeri(lipase TL) is investigated as a biocatalyst for the formation of an acid–epoxy chemical network. Molecular model reactions are performed by reacting 2-phenyl glycidyl ether and hexanoic acid in bulk, varying two parameters: temperature and water content. Characterizations of the formed products by1H NMR spectroscopy and gas chromatography–mass spectrometry combined with enzymatic assays confirm that lipase TL is able to simultaneously promote acid–epoxy addition and transesterification reactions below 100 °C and solely the acid–epoxy addition after denaturation atT> 100 °C. A prototype bio-based chemical network with β-hydroxyester links was obtained using resorcinol diglycidyl ether and sebacic acid as monomers with lipase TL as catalyst. Differential scanning calorimetry, attenuated total reflection, and swelling analysis confirm gelation of the network.

International audience; The intrinsic compliance of soft robots provides safety, a natural adaptation to its environment, allows to absorb shocks, and protects them against mechanical impacts. However, a literature study shows that the soft polymers used for their construction are susceptible to various types of damage, including fatigue, overloads, interfacial debonding and cuts, tears and perforations by sharp objects. An economic and ecological solution is to construct future soft robotic systems out of self-healing polymers, incorporating the ability to heal damage. This review paper proposes criteria to evaluate the potential of a self-healing polymer to be used in soft robotic applications. Based on these soft robotics requirements and on defined performance parameters of the materials, linked to the mechanical and healing properties, the different types of selfhealing polymers already available in literature are critically assessed and compared. In addition to a description of the state of the art on self-healing soft robotics, the paper discusses the driving forces and limitations to spur the interdisciplinary combination between self-healing polymer science and soft robotics.

Living anionic polymerization gives access to well-defined polymers, but it demands strict purification of reagents and solvents. This work presents the azaanionic polymerization (AAROP) of aziridines as a robust living polymerization technique, with the ease of controlled radical polymerizations. AAROP does not require inert atmosphere and remains living in the presence of large amounts of water or alcohols. Mesyl-, tosyl-, or brosyl-activated aziridines were polymerized with up to 100-fold excess of a protic impurity with respect to the initiator and still being active for chain extension. This allowed the preparation of polyols by anionic polymerization without protective groups, as only minor initiation occurred from the alcohols. The tolerance toward protic additives lies in the electron-withdrawing effect of the activating groups, decreasing the basicity of the propagating species, while maintaining a strong nucleophilic character. In this way, competing alcohols and water are only slightly involved...

International audience; The ring-opening polymerization of N-tosyl aziridines, in the presence of 1,3-bis(isopropyl)-4,5(dimethyflimidazol-2-ylidene as an organocatalyst and an N-tosyl secondary amine as initiator mimicking the growing chain, provides the first metal-free route to well defined poly(aziridine)s (PAz) and related PAz-based block copolymers.

Polyamides with different percentages of aromatic/aliphatic units and molar masses were synthesized in a one-step bulk copolymerization of e-caprolactam and ethyl 4-aminobenzoate at 140 °C keeping the same experimental conditions basically used for the synthesis of polyamides by anionic ring opening polymerization (AROP). Copolyamides were characterized by NMR spectroscopy, size exclusion chromatography and thermo-mechanical analysis (DSC, TGA and DMA). This methodology, combining simultaneous anionic ring-opening and condensation reactions, affords a new route to introduce aromatic amides into an aliphatic polyamide backbone and tune its properties. Modified polyamides 6 (PA6) obtained from e-caprolactam by an activated monomer mechanism and containing up to 17% mol of aromatic moiety were prepared. The new materials exhibited in particular high thermal stability and high glass transition temperature up to 79 °C.

Commercial aminoalcohols, namely, 2-(methyl amino)ethanol (1) and diethanolamine (2), are investigated as direct initiators, i.e., with no need of protection of the hydroxyl groups, for the N-heterocyclic carbene-organocatalyzed ring-opening polymerization (NHC-OROP) of 2-methyl-N-p-toluenesulfonyl aziridine. NHC-OROP’s are performed at 50 °C in tetrahydrofuran, in the presence of 1,3-bis(isopropyl)-4,5(dimethyl)imidazol-2-ylidene (Me5-IPr) as organocatalyst. Thus, nonprotected and nonactivated aminoalcohol initiators 1 and 2 provide a direct access to metal-free α-hydroxy-ω-amino- and α,α′-bis-hydroxy-ω-amino telechelics on the basis of polyaziridine (PAz), respectively. Excellent control over molar masses, narrow dispersities (Đ ≤ 1.20), and high chain-end fidelity are evidenced by combined analyses, including NMR spectroscopy, size exclusion chromatography, and MALDI ToF mass spectrometry. The amino-initiated NHC-OROP is therefore tolerant to the presence of nonprotected hydroxyl group(s). The as-obtai...

Polyaziridines (PAz) were synthesized for the first time by the 1,3-bis(isopropyl)-4,5(dimethyl)imidazol-2-ylidene-organocatalyzed ring-opening polymerization (OROP) of 2-alkyl- N - p -toluenesulfonyl aziridine (alkyl = methyl or phenyl), in the presence of both functional activated amine and non-functional non-activated amine initiators. Thus, not only an allyl-functionalized N -sulfonyl amine could serve as initiator, but also trimethylsilyl azide allowed introducing an allyl and an azido functionality in α-position of PAz chains, respectively. A non-activated and commercially available secondary amine, such as di- n -butylamine, also effectively initiated the OROP of N -tosylaziridines. Excellent control over molar masses, high chain-end fidelity and narrow dispersities ( Ð ≤ 1.20) were achieved, as attested by NMR spectroscopy, size exclusion chromatography and MALDI ToF mass spectrometry. PAz precursors consisting of the alkene or the azido functionality could further be derivatized, highlighting the accessibility of those functional groups. Overall, this N -heterocyclic carbene-OROP methodology offers a metal-free route to well-defined α-functionalized PAz.

International audience; Mechanistic insights into bulk hydrogen-transfer polymerization of acrylamide initiated by t-BuONa are proposed in this study where attention is particularly given to the initiation and propagation steps. This anionic polymerization methodology led to the synthesis of polyamide-3 with controlled molar masses. NMR, SEC, and MALDI-ToF characterizations are supporting the chemical structures and the macromolecular dimensions of polyamide-3. The polymerization is completed in a few minutes depending on the targeted molar mass as confirmed by a complementary temperature vs time study. DSC and TGA measurements enabled the determination of the glass transition and degradation temperatures at 88 and 357 degrees C, respectively. Side reactions such as branching, transfer to monomer, and formation of polyacrylamide units were shown to occur and depend on the amount of base added. The formation of imide groups is also observed due to the formation of ammonia in the polymerization medium.

Hybrid networks, including physical and chemical cross-links, were synthesized from biosourced fatty acid fragments, linked to each other by a controlled number of nonexchangeable ether bonds, exchangeable ester bonds, and noncovalent hydrogen bonds. The mechanical properties of these networks are tuned by the ratio of di- versus tetraepoxide and the stoichiometry acid/ epoxy. Creep tests and insolubility demonstrated the vitrimer or vitrimer-like nature of the resulting materials. The thermostimulated welding ability of the materials was exploited to incorporate strain sensors by embedding electrically conductive fibers into the rubbery vitrimer matrix. Both the efficiency of the welding procedure at moderate temperatures (80 °C) and the tunability of mechanical properties are attractive assets for the effective incorporation of thermodegradable conductive fibers while preserving their mechanical and electrical integrity. The mechanical and electrical behaviors of the sensor composites were simultaneously tested, either in quasi-static or in cyclic tensile experiments, at room temperature and at a larger distance from Tg of the matrices. The study emphasizes the importance of matching Young’s moduli of components in composite samples, which is strongly temperature-dependent.