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Here we describe the main synthetic approaches for the production of CO2-based polycarbonates and their emerging end-of-life scenarios by chemical re-/up-cycling.

The inherent skeletal and thermal features to forge polymers by step-growth polymerization are conflicting with any depolymerization strategies via cascade back-biting reactions that necessitate adequate ceiling temperature, spacers, and functionalities to create cyclic compounds. Here, we report the edition of step-growth poly(carbonate-urea)s and poly(carbonate-amide)s that are depolymerized on demand into their native precursor or added-value offspring oxazolidinones, together with a hemiacetal cyclic carbonate. The unprotected in-chain secondary amide or urea functionalities of the polymers trigger their degradation via cascade ring-closing events upon a thermal switch (from 25 to 80 °C) in the presence of an organic base as a catalyst. Although most studies are realized in solution for understanding the deconstruction process, the polymers are also fully degraded in 2 h in neat conditions without any catalyst at 150 °C. At 80 °C, the organic base is required to accelerate the process. On the road to sustainability and circularity, we validate the concept by exploiting monomers designed from waste CO2 and upcycled commodity plastics. Ultimately, these polymers are selectively depolymerized from plastic mixtures composed of commodity poly(ethylene terephthalate) and polycaprolactone, offering new options for recycling plastic waste mixtures while delivering high-value-added chemicals.

The catalyst-free synthesis of urethanes from cyclic iminocarbonates, used as masked isocyanates, and soft nucleophiles (i.e. carboxylic acids and thiols) has been studied. Remarkably, the ring-opening reaction was fully site-selective (i.e. methylene). The disclosed method showed high functional group tolerance towards carboxylic acids bearing alkyl-, alkenyl-, ketone-, pyrone- and hydroxyl groups. This methodology was further applied for the construction of regioregular functional polyurethanes by step-growth copolymerization of cyclic bisiminocarbonates and dicarboxylic acids or dithiols. M-w up to 34 000 g mol(-1) was obtained in a fully atom-economical manner using an equimolar amount of both monomers.

Ethylene–vinyl alcohol copolymers (EVOHs) are important materials available in a variety of compositions and valued in countless applications. In spite of their great adaptability offered by the ad...

For 80 years, polyisocyanates and polyols were central building blocks for the industrial fabrication of polyurethane (PU) foams. By their partial hydrolysis, isocyanates release CO

The polyaddition between dicyclic carbonates and diamines leading to poly(hydroxy urethane)s (PHUs) has emerged as the preferred method for the synthesis of green, non-isocyanate polyurethanes. However, when proposed for use as structural adhesives, the long times for completion of aminolysis of the 5-membered cyclic carbonates under ambient conditions force the use of complementary chemistries to accelerate the curing process. In this work, a system that combines an amino-terminated PHU (NH2-PHU-NH2), an epoxy resin, and a thiol compound was employed to develop high-shear strength PHU-epoxy hybrid adhesives able to cure at room temperature in short times. A NH2-PHU-NH2 prepolymer synthesized by using a sub-stoichiometric quantity of dicyclic carbonates was mixed with a bisphenol A-based epoxy resin for the preparation of the structural adhesive. While this adhesive showed good lap-shear strength and shear resistance under static load and temperature, the curing process was slow. In order to speed up the curing process, a thiol (trimethylolpropane tris(3-mercapto propionate)) was added and its impact on the curing process as well as on the adhesive properties was evaluated. The trifunctional thiol additive allowed for faster curing in the presence of the 1,1,3,3-tetramethylguanidine basic catalyst. Moreover, a combination of NH2-PHU-NH2 and the thiol as curing agents for the epoxy resin resulted in adhesives with superior toughness, without any deterioration of the ultimate lap-shear strength or shear resistance under load and temperature, making these adhesives suitable for high-demand applications in the automotive industry. The authors would like to acknowledge the technical and human support provided by SGIker (UPV/EHU and ERDF, EU) . A.G.-L. would like to acknowledge the University of the Basque Country for the predoctoral fellowship received to carry out this work and Dr. Nora Aranburu for the help with the lap-shear measurements. ORIBAY Group Automotive also wants to acknowledge HAZITEK program for the financial support of the project no ZL-2019/00193. The authors want to acknowledge the financial support of the EU through the project NIPU-EJD 9555700. C.D. is FNRS Research Director and would like to thank FNRS for financial support.

Polyurethane (PU) adhesives and coatings are widely used to fabricate high-quality materials due to their excellent properties and their versatile nature, which stems from the wide range of commercially available polyisocyanate and polyol precursors. This polymer family has traditionally been used in a wide range of adhesive applications including the bonding of footwear soles, bonding of wood (flooring) to concrete (subflooring), in the automotive industry for adhering different car parts, and in rotor blades, in which large surfaces are required to be adhered. Moreover, PUs are also frequently applied as coatings/paints for automotive finishes and can be applied over a wide range of substrates such as wood, metal, plastic, and textiles. One of the major drawbacks of this polymer family lies in the use of toxic isocyanate-based starting materials. In the context of the REACH regulation, which places restrictions on the use of substances containing free isocyanates, it is now urgent to find greener routes to PUs. While non-isocyanate polyurethanes (NIPUs) based on the polyaddition of poly(cyclic carbonate)s to polyamines have emerged in the past decade as greener alternatives to conventional PUs, their industrial implementation is at an early stage of development. In this review article, recent advances in the application of NIPUs in the field of adhesives and coatings are summarized. The article also draws attention to the opportunities and challenges of implementing NIPUs at the industrial scale.

Partly or fully renewable (co)polymers are gaining interest in both academia and industry. Polyethylene is a widely used polymer, classically derived from fossil fuels, with a high versatility stemming from the introduction of comonomers altering the mechanical properties. The introduction of renewable functionalities into this polymer is highly attractive to obtain functional, tunable, and at least partially renewable polyethylenes. We herein report the introduction of biosourced cyclic carbonates into polyethylene using organometallic-mediated radical polymerization under mild conditions. Molecular weights of up to 14 600 g mol

Green resources for lithium-based batteries excite many researchers due to their eco-friendly nature. In this work, a sustainable bio-based solid-state electrolyte was developed based on carbonated soybean oil (CSBO), obtained by organocatalyzed coupling of CO2 to epoxidized soybean oil. CSBO coupled with lithium bis(trifluoromethanesulfonyl)imide salt on a bio-based cellulose separator resulted in free-standing membranes. Those membranes on electrochemical measurements exhibited ionic conductivity of around 10−3 S cm−1 at 100 °C and around 10−6 S cm−1 at room temperature with wide electrochemical stability window (up to 4.6 V vs. Li/Li+) and transference number up to 0.39 at RT. Further investigations on the galvanostatic charge-discharge of LiFePO4 cathodes with CSBO-based electrolyte membranes and lithium metal anodes delivered the gravimetric capacity of 112 and 157 mAh g−1 at RT and 60 °C, respectively, providing a promising direction to further develop bio-based solid electrolytes for sustainable solid-state lithium batteries.

We report an approach to fabricate self-blown nonisocyanate polyurethane (NIPU) foams by capitalizing on the divergent chemistries of amines with cyclic carbonates─creating the polymer network─and thiolactone─delivering

We investigate the scope of the organocatalyzed step-growth copolymerization of CO2-sourced exovinylene bicyclic carbonates with bio-based diols into polycarbonates. A series of regioregular poly(oxo-carbonate)s were prepared from sugar- (1,4-butanediol and isosorbide) or lignin-derived (1,4-benzenedimethanol and 1,4-cyclohexanediol) diols at 25 degrees C with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a catalyst, and their defect-free structure was confirmed by nuclear magnetic resonance spectroscopy studies. Their characterization by differential scanning calorimetry and wide-angle X-ray scattering showed that most of them were able to crystallize. When the polymerizations were carried out at 80 degrees C, some structural defects were introduced within the polycarbonate chains, which limited the polymer molar mass. Model reactions were carried out to understand the influence of the structure of alcohols, the temperature (25 or 80 degrees C), and the use of DBU on the rate of alcoholysis of the carbonate and on the product/linkage selectivity. A full mechanistic understanding was given by means of static- and dynamic-based density functional theory (DFT) calculations showing the determining role of DBU in the stability of intermediates, and its important role in the rate-determining steps is revealed. Furthermore, the origin of side reactions observed at 80 degrees C was discussed and rationalized by DFT modeling. As impressive diversified bio-based diols are accessible on a large scale and at low cost, this process of valorization of carbon dioxide gives new perspectives on the sustainable production of bioplastics under mild conditions.

In this communication, an atmospheric one-step plasma-based method is reported for the simultaneous synthesis and deposition of robust redox-active catechol-rich polymers. The bioinspired films are characterized by combining various analytical techniques, including IR, XPS, AFM and SIMS, and their potentials as organic cathode materials for lithium ion battery demonstrated. The influence of the coating thickness on the applicative properties of the films is also investigated.

Temperature influences drastically the physical properties of polymer powders. In the present study, the packing dynamics of polymer powders has been investigated with a modified version of GranuPack instrument, which is an improvement of the classical tapped density measurement. After the filling procedure, the sample is heated and the evolution of the density is measured after each tap. For a selection of four polymers (polyamide 12, Polystyrene, Polyvinyl chloride and a thermoplastic polyurethane), the influence of temperature on the Hausner ratio and on the packing dynamics are analysed. We show that the packing dynamics is drastically influenced by temperature even far below the melting temperature T m for semi-crystalline polymers and far below the glass-transition temperatures T g for amorphous polymers. In addition, we show that the analysis of the packing dynamics at different temperatures allows to determine a characteristic temperature corresponding to the onset of caking. Finally, we show that this temperature is coherent with Differential Scanning Calorimetry (DSC) analysis.

Poly(oxazolidone) is an emerging class of polyurethanes (PUs) that is easily accessible by an isocyanate-free pathway via the step-growth copolymerization of CO₂-based monomers (bis(α-alkylidene cyclic carbonate)s) with primary diamines at room temperature. Here, we explore the scope and limitation of this process by investigating the influence of the diamine and the reaction conditions on the structure and macromolecular parameters of the polymer. Less hindered diamines (aliphatic and benzylic) provide selectively poly(hydroxyoxazolidone)s, whereas the bulkier ones (cycloaliphatic) furnish polymer chains bearing two types of linkages, oxo-urethane and hydroxyoxazolidone ones. The increase of the reaction temperature or the addition of DBU as a catalyst enables to accelerate the polymerizations. The quantitative polymer dehydration is also achieved by refluxing in acetic acid, providing a new class of unsaturated poly(oxazolidone)s composed of α-alkylidene oxazolidone linkages (for hindered polymers) or a mixture of α- and β-alkylidene oxazolidone linkages (for the less hindered ones). These unsaturated poly(oxazolidone)s present a high glass transition temperature (90 °C ≤ Tg ≤ 130 °C) and a remarkable thermal stability (Td > 360 °C), rendering these polymers attractive for applications requiring high temperatures. This work is therefore opening an avenue to novel functional isocyanate-free PUs, with the pendant hydroxyl or olefin groups that are expected to be easily derivatized.

Non-isocyanate polyurethanes (NIPUs) based on five-membered cyclic carbonates have emerged as the most promising alternative to replace more toxic, conventional polyurethanes. However, the low reac...

[EN] Poly(hydroxy urethane)s (PHUs) based on 5-membered cyclic carbonates have emerged as sustainable alternatives to conventional isocyanate-based polyurethanes. However, while from the point of view of sustainability they represent an improvement, their properties are still not competitive with conventional polyurethanes. In this work, the potential of PHUs as reversible hot-melt adhesives is discussed. We found that with a judicious choice of reagents (ie., the dicyclic carbonate and diamine), the detrimental hydrogen bonding between the soft segment of the chains and the pendant hydroxyl groups was partially avoided, thus imparting PHUs with hot-melt adhesion properties (i.e., adhesion at elevated temperatures and cohesiveness at a temperature lower than T-g/T-m). The importance of a balanced hard to soft segment ratio, along with the relevance of the chain extender in the final properties, is highlighted. Addition of aliphatic diamines (HMDA, 1,12-DAD) resulted in rubbery materials, while the employment of cydoaliphatic (CBMA) or aromatic ones (MXDA, PXDA) led to materials with hot-melt adhesive properties. The thermoreversibility of all compositions was assessed by rebonding specimens after lap-shear tests. Lap-shear strength values that were comparable to the virgin adhesives were observed. The breaking and reformation of hydrogen bonding interactions was demonstrated by FTIR measurements at different temperatures, as well as by rheological frequency sweep experiments. In order to mitigate the negative impact of the low molar mass PHUs and to enhance the service temperature of the adhesives, a hybrid PHU was prepared by adding a small amount of an epoxy resin, which acts as a cross-linker. These hybrid PHUs maintain the thermoreversibility displayed by thermoplastic PHUs while providing better adhesion at elevated temperatures. We believe that this work provides some important insights into the design of PHU-based hot-melt adhesives. The authors would like to acknowledge the technical and human support provided by SGIker (UPV/EHU and ERDF, EU). A.G.-L. acknowledges the University of the Basque Country for the predoctoral fellowship received to carry out this work. The authors would also like to acknowledge the technical support provided by Amaia Agirre for the GPC analysis. ORIBAY Group Automotive also wants to acknowledge the HAZITEK program for the final support of the project n degrees ZL-2019/00193. This project has been partly supported by the European Union's Horizon 2020 research and innovation program under Marie Sklodowska-Curie grant agreement No. 955700. C.D. thanks FNRS for financial support. The authors of Liege thank the "Fonds National pour la Recherche Scientifique" (F.R.S.-FNRS) and the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO) for financial support in the frame of the EOS project n degrees O019618F (ID EOS: 30902231). C.D. is F.R.S.-FNRS Research Director.

Carbon dioxide is a renewable, inexhaustible, and cheap alternative to fossil resources for the production of fine chemicals and plastics. It can notably be converted into exovinylene cyclic carbonates, unique synthons gaining momentum for the preparation of an impressive range of important organic molecules and functional polymers, in reactions proceeding with 100 % atom economy under mild operating conditions in most cases. This Review summarizes the recent advances in their synthesis with particular attention on describing the catalysts needed for their preparation and discussing the unique reactivity of these CO

Formaldehyde (FA) is a harmful chemical product largely used for producing resins found in our living spaces. Residual FA that leaches out the resin contributes to our indoor air pollution and causes some important health issues. Systems able to capture this volatile organic compound are highly desirable; however, traditional adsorbents are most often restricted to air filtration systems. Herein, we report novel waterborne coatings that are acting as a FA sponge for indoor air decontamination. These coatings, of the poly(hydroxyurethane) (PHU) type, rich in primary amine groups, are prepared by the polyaddition of a hydrosoluble dicyclic carbonate to a polyamine in water at room temperature under catalyst-free conditions. We highlight the importance of the choice of the polyamine on the curing rate of the formulation and on the FA capture ability of PHU. The excellent FA capturing ability of the best candidate is rationalized by investigating the action mode of the polyamine used to construct PHUs. With poly(vinyl amine), FA is covalently and permanently bound to PHU, with no release over time. The performance of the coating in FA abatement is impressive, with more than 90% of captured FA after one day of contact. The facility to prepare these transparent and colorless coatings from waterborne formulations gives access to new efficient indoor air depolluting solutions, potentially applicable to various surfaces of our living spaces (wall, ceiling, etc.).

Polycarbonates bearing linear carbonate linkages and polyether segments have demonstrated to be highly attractive solid electrolyte candidates for the design of safe energy storage devices, for exa...

Radical polymerization of exo-methylene cyclic monomers is a straightforward strategy for preparing polymers with pendant heterocycles used as protective groups for reactive functions. In spite of their availability and possible chemical transformations, so far, methylene oxazolidinones have been disregarded in the field of macromolecular synthesis. This work reports the radical (co)polymerization of 4,4-dimethyl-5-methyleneoxazolidin-2-one (DMOx) and the transformation of the pendant oxazolidinone groups into vicinal amino-alcohol functions. DMOx was produced through an optimized procedure of carboxylative cyclization of dimethylpropargylamine. In addition to the conventional radical (co)polymerization of DMOx, we considered its reversible deactivation radical copolymerization with VAc by organometallic-mediated radical polymerization (OMRP) and reversible addition fragmentation chain transfer (RAFT). The ability of these methods to produce well-defined copolymers was studied as well as their respective reactivity ratios. Finally, the poly(DMOx-co-VAc) was converted into vicinal amino-alcohol functional poly(vinyl alcohol)s presenting peculiar multi-responsive behavior, namely pH-, thermal- and metal-ion sensitivity.

Organic redox-active materials are actively being searched as a more sustainable alternative to traditional inorganic cathodes used in rechargeable batteries. Among the different types of organic cathodes, redox polymers based on catechol groups show high energy storage capacities. In this article, we show how the introduction of pyridine groups can shift the potential of catechol containing polymers towards more positive values further enhancing their energy storage capacities. For this purpose, we carried out the synthesis of redox-active polymer nanoparticles having catechol and pyridine functionalities. Spherical nanoparticles between 150 and 300 nm were synthesized by a surfactant-free emulsion polymerization method by copolymerization of dopamine methacrylamide and 4-vinyl pyridine. The chemical composition of the nanoparticles was confirmed by FTIR spectroscopy which shows the presence of catechol-pyridine hydrogen bonding. Thermal analyses (DSC, TGA) confirmed the glass transition of the nanoparticles between 158 and 190 °C and high thermal stability with a degradation temperature of 300 °C at 5% weight loss (Td5%). The electrochemical characterization of the redox-active polymer nanoparticles show that the redox potential of the catechol group was not affected by the presence of the pyridine in acidic electrolytes (E1/2 = 0.45 V versus Ag/AgCl). However, in organic electrolytes containing a lithium salt the redox potential of the catechol nanoparticles shifted from 0.27 V for catechol homopolymer, to 0.56 V for the catechol-pyridine copolymer. This positive potential gain could be associated to the proton trap effect as indicated by DFT calculations. Finally, the beneficial effect of the proton trap effect onto the performance of lithium-ion-polymer battery was demonstrated. The lithium vs. polymer cells showed a promising practical high voltage organic cathode (3.45 V vs. Li+/Li), excellent rate performance (up to 120C) and high capacity retention after cycling (74% after 800 cycles). Fil: Gallastegui, Antonela. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Minudri, Daniela. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Casado, Nerea. Universidad del País Vasco. Polymat; España Fil: Goujon, Nicolas. Universidad del País Vasco. Polymat; España Fil: Ruipérez, Fernando. Universidad del País Vasco. Polymat; España Fil: Patil, Nagaraj. Instituto Imdea Energia; España Fil: Detrembleur, Christophe. Universidad de Lieja; Bélgica Fil: Marcilla, Rebeca. Instituto Imdea Energia; España Fil: Mecerreyes, David. Universidad del País Vasco. Polymat; España. Ikerbasque; España

The synthesis of ethylene-based block copolymers (BCPs) by using a single radical polymerization technique is attractive but remains to be a great challenge. The main difficulty relates to the diff...

The study deals with the catalytic cyclocarbonation of epoxides to produce monomers used in the synthesis of polyurethane. A benchmark study of the textural properties of silica-based, doped or not, supports enabling the identification and optimization of the key parameters affecting the catalytic activity is reported. The results reveal that ammonium catalysts immobilized onto mesostructured supports with high surface area and low aggregation show better catalytic performances than analogue catalysts grafted onto microstuctured ones. While a high external surface area favours the grafting of ammonium salt, pore size must be large enough to enhance the accessibility of both carbon dioxide and epoxides to the catalytic sites. The activity of heterogeneous catalysts was evaluated for a model coupling reaction between carbon dioxide and propylene glycol diglycidylether. Using appropriated supports, cyclocarbonation yields are found to be higher in the presence of the heterogeneous catalyst in comparison with the homogeneous one. These results allow to confirm the beneficial effect of the presence of residual OH silanol groups at the surface of the support, which activate epoxide through forming of hydrogen bonds.

alpha-Alkylidene cyclic carbonates (alpha CCs) recently emerged as attractive CO2-sourced synthons for the construction of complex organic molecules. Herein, we report the transformation of alpha CCs into novel families of sulfur-containing compounds by organocatalyzed chemoselective addition of thiols, following a domino process that is switched on/off depending on the desired product. The process is extremely fast and versatile in substrate scope, provides selectively linear thiocarbonates or elusive tetrasubstituted ethylene carbonates with high yields following a 100 % atom economy reaction, and valorizes CO2 as a renewable feedstock. It is also exploited to produce a large diversity of unprecedented functional polymers. It constitutes a robust platform for the design of new sulfur-containing organic synthons and important families of polymers.

Organic electrode materials capable of reversible coordination/uncoordination of both mono- and multivalent ions in aqueous electrolytes are desired to develop safe, sustainable, and cost-effective water-based batteries. Here, we demonstrate the universality of bioinspired redox-active polymers bearing catechol pendants to reversibly coordinate/uncoordinate numerous cations including H+ and Li+ to Zn2+ and Al3+ with fast kinetics and ultralong cyclability. This unprecedented versatility is based on a catecholato–metal cation complex (Cat2–(mMn+)) charge storage mechanism that dictates the overall electrochemistry: formation of stronger complexes in M+ < M2+ < M3+ order resulted in a huge redox potential increment that might be used to tune the operating voltage of the battery.

With higher energy density, flexibility, safe operation at both room temperature as well as high temperature, solid-state batteries technology has been strongly looked upon as superior diversion from conventional liquid electrolytes-based lithium batteries. Among various other class of polymers, there is strong need to focus on sustainable and yet better alternatives other than most researched polyethylene oxide (PEO). Poly(hydroxyurethanes) (PHU) owing to their high degree of structural tunability can be interesting candidates for Solid polymer electrolyte (SPE). Here, we synthesized bio-based PHU networks by facile ring-opening polymerization of carbonated soybean oil (CSBO) without catalyst. The existence of polyether and polyester provides the PHU network with soft segments while urethane linkage with hard segments. The lower Tg with higher thermal stability widespread its application at elevated temperature without melting and significant degradation. PHU shows remarkable adhesive properties to the surface of metal speculating better interfacial contact and stability. The electrochemical investigations exhibited decent ionic conductivity (> 10-4 at 60o C), electrochemical stability window (ESW > 4.5 V vs. Li/Li+) and transport properties allowing it to be explored for high voltage cathodes. Lithium ferrophosphate (LiFePO4) cells with PHU also demonstrated promising charge-discharge (> 100 mAhg-1 at 60o C) with the li-metal anode. The attempt to develop bio-based batteries materials are much required added step toward green and clean energy for a sustainable future.

Solid state batteries are of wide interest owing to their high energy density and safety. Their stability with high voltage cathodes is not new to the researchers and are advantageous in various terms. Although ethylene oxide side chains being one of the most studied system also suffers from serious setback with its prime backbone. Here in our work, we studied the effect of terminal group of linear and tri-arm polyethylene glycol (PEG-OH) by converting it to carbonate-ketone (Carb-ket) from hydroxyl. We synthesized the polyethylene carb-ket (TPEG-carb-ket) terminal by ring opening reaction. The carb-ket functionality at the chain end not only increase the electrochemical stability window > 4.47 V but also limits the parasitic reactions with lithium metal stabilising SEI at the interface. The latter demonstrated the superior galvanostatic charge-discharge of LiFePO4 using as synthesized electrolyte loaded with LiTFSI salts as compare to similar chain length PEG-OH. This make the vast impact on controlling the undesired decomposed products at the interface to facilitate the high coulombic efficiency and capacity retention The TPEG-carb-ket also hinted at stable interface with lithium as a result of stripping and plating for more than 1200 h. These experiment results provide important insights backed by AIMD simulations in comparison with hydroxyl terminal system. Our study would aide with the major step on improving the higher voltage cathode with superior performance in the lithium batteries.

Polyurethane (PU) foams are indisputably daily essential materials found in many applications, notably for comfort (for example, matrasses) or energy saving (for example, thermal insulation). Today, greener routes for their production are intensively searched for to avoid the use of toxic isocyanates. An easily scalable process for the simple construction of self-blown isocyanate-free PU foams by exploiting the organocatalyzed chemo- and regioselective additions of amines and thiols to easily accessible cyclic carbonates is described. These reactions are first validated on model compounds and rationalized by DFT calculations. Various foams are then prepared and characterized in terms of morphology and mechanical properties, and the scope of the process is illustrated by modulating the composition of the reactive formulation. With impressive diversity and accessibility of the main components of the formulations, this new robust and solvent-free process could open avenues for construction of more sustainable PU foams, and offers the first realistic alternative to the traditional isocyanate route.

Polyurethane hydrogels are attractive materials finding multiple applications in various sectors of prime importance; however, they are still prepared by the toxic isocyanate chemistry. Herein the facile and direct preparation in water at room temperature of a large palette of anionic, cationic, or neutral polyurethane hydrogels by a non-isocyanate route from readily available diamines and new hydrosoluble polymers bearing cyclic carbonates is reported. The latter are synthesized by free radical polymerization of glycerin carbonated methacrylate with water-soluble comonomers. The hydrogel formation is studied at different pH and its influence on the gel time and storage modulus is investigated. Reinforced hydrogels are also constructed by adding CaCl2 to the formulation that in-situ generates CaCO3 particles. Thermoresponsive hydrogels are also prepared from new thermoresponsive cyclic carbonate bearing polymers. This work demonstrates that a multitude of non-isocyanate polyurethane hydrogels are easily accessible under mild conditions without any catalyst, opening new perspectives in the field.

Mussel wet adhesion is known for its outstanding strength on a variety of surfaces. On the basis of the hypothesis that 3,4-dihydroxyphenylalanine, a catecholic amino acid, governs mussel adhesion, chemists have put much effort into the design of adhesive synthetic polymers containing catechols. However, the exceptional properties exhibited by the native proteins were hardly captured. The attempts to make those polymers stick to wet inorganic surfaces resulted in low adhesive forces. Here we synthesized poly(dopamine acrylamide) and measured the interaction forces with various inorganic surfaces using atomic force microscopy-based single-molecule force spectroscopy. We show that hydroxylation of the surface plays a pivotal role on the formation of strong bonds. We demonstrate that depending on the conditions, the whole range of interactions, from weak interactions to covalent bonds, can come into play.

International audience; Herein, we propose a critical study balancing two metal-free dual activating systems, namely DBU/EtBr and TEA/TsCl, for the coupling of CO2 with 1,x-diols to afford (a)cyclic carbonates. In-situ ATR-IR monitoring correlated with DFT calculations led to mechanism propositions for the model formation of propylene carbonate from propylene glycol. Kinetics upon various experimental conditions were established for the first time, leading to an optimized synthetic protocol. The substrates scope was then investigated and selectivities toward the formation of cyclic or linear carbonates were correlated to the dual activating system and the diol structure. By choosing the suitable organic dual activating system, one is able to control the product selectivity to substituted ethylene-or trimethylene carbonate and/or acyclic compounds, providing a powerful tool to synthesize CO2-based precursors that are highly relevant for organic and polymer chemistry from ubiquitous building blocks.

Carbon dioxide offers an accessible, cheap and renewable carbon feedstock for synthesis. Current interest in the area of carbon dioxide valorisation aims at new, emerging technologies that are able to provide new opportunities to turn a waste into value. Polymers are among the most widely produced chemicals in the world greatly affecting the quality of life. However, there are growing concerns about the lack of reuse of the majority of the consumer plastics and their after-life disposal resulting in an increasing demand for sustainable alternatives. New monomers and polymers that can address these issues are therefore warranted, and merging polymer synthesis with the recycling of carbon dioxide offers a tangible route to transition towards a circular economy. Here, an overview of the most relevant and recent approaches to CO2-based monomers and polymers are highlighted with particular emphasis on the transformation routes used and their involved manifolds.

Charged nanofibers were prepared by electrospinning (ESP) poly(e-caprolactone) with a copolymer bearing carboxylic acid functions. The presence of these functions allowed exposing some negative charges on the fiber surface, by dipping the fibers in a phosphate buffer. A layer of chitosan, a polycation in acidic medium, was then deposited on the nanofiber surface, thanks to electrostatic attraction. Fibers were characterized at each step of the process and the influence of the copolymer architecture on chitosan deposition was discussed. The antibacterial activity of the resulting fibers was finally assessed.

International audience; In the past few decades, various nanovehicles have been developed as drug delivery systems, in which inorganic and organic components are integrated within a nano-object. Upon the application of remote stimuli, e.g. alternating magnetic field, near infrared or ultrasound radiations, the release of guest molecules can be triggered in a quite controlled manner. Herein, we review different hybrid nanostructures which have already been reported for the remotely triggered release, such as those based on (1) host–guest conjugates, (2) core–corona nanoparticles, (3) polymer nanogels, (4) polymer micelles, (5) liposomes, (6) mesoporous silica particles and (7) hollow nanoparticles. Moreover, we also summarize six underlying mechanisms that govern such a kind of remotely triggered release behaviours: (1) enhanced diffusion and/or permeation, (2) thermo- or photo-labile bond cleavage, (3) fusion of phase-changed materials, (4) photo-induced isomerisation, (5) thermo-induced swelling/de-swelling of thermo-responsive polymers, and (6) destruction of the nanostructures. The ways in which different components are incorporated into an integrated hybrid nanostructure and how they contribute to the remotely triggered release behaviours are detailed.

In light of fossil fuel depletion and a general necessity for sustainable development, the synthesis of polymers from renewable resources is gaining more and more importance, yet industrially relevant radical polymerizations still struggle with the incorporation of renewable resources as the number of natural molecules containing suitable double bonds is limited. Herein, we present the sustainable synthesis of nonactivated allylic and olefinic carbonate monomers from renewable resources in a solventless one-pot transesterification reaction. We subsequently confirm the first controlled radical copolymerization of such challenging nonactivated monomers with vinyl acetate, in which molecular weights above 10 000 g·mol–1 were reached. The controlled nature of the copolymerizations was verified by the low dispersities obtained and the linear increase in molecular weights with conversion. The so-prepared copolymers were purified using sustainable extractions by supercritical carbon dioxide (scCO2), which allowe...

Green routes for the synthesis of high-performance isocyanate-free polyurethane coatings and adhesives are intensively searched for. In this article, we report a solvent- and isocyanate-free formul...

We report on the synthesis of a new polymer ionic liquid (PIL) based on polyvinylimidazolium bearing a pendent nitroxide radical on each monomer unit. Firstly, the quaternization of 1-vinylimidazole by a brominated alkoxyamine, i.e. a protected tetramethylpiperidinyloxy (TEMPO) nitroxide, was achieved. Then, the bromide anion was substituted by anion exchange reaction for the bis(trifluoro-methanesulfonyl)imide (TFSI) anion. The as-obtained monomer was successfully polymerized by free radical polymerization at low temperature (40 °C) by using 2,2′-azobis(4-methoxy-2.4-dimethyl valeronitrile) as initiator. Finally, the C O bond of the alkoxyamine pendant groups was thermally cleaved releasing the redox-active TEMPO nitroxide radicals. The PIL bearing TEMPO groups was coated onto a carbon nanotubes buckypaper and tested as cathode in a lithium ion battery. Such battery remarkably exhibits a high charge/discharge rate capability, e.g. at 60C the full charge is reached in 1 min and a high cycling stability; 100% of the initial capacity 60 mA h/g is kept after 1300 cycles.

This review reports the recent advances in the most important and straightforward synthetic protocols for incorporating catechols into (bio)polymers, and discusses the emerging applications of these innovative multifunctional materials in biomedical, energy storage and environmental applications. In the last five years, new well-defined polymer structures with tuneable composition and functionality were introduced by the careful combination of catechol protection/deprotection chemistry with controlled polymerization techniques. These new synthetic pathways have facilitated the optimal design of the material that perfectly fits the target application. Although most current researches exploit the adhesive properties of catechols for designing glues or (multi)functional coatings, recent breakthroughs have shown that catechols have much more to offer in other areas, especially those where they act as reversible redox units to store electrons/metal cations for the design of “next-generation” safe, economical and sustainable energy storage devices. These emerging applications of potential high impact in our daily life are now discussed in this review together with the new synthetic routes to unprecedented precise catechol-bearing polymers. Additional objectives of this review are to discuss some important critical issues regarding the stability and reactivity of catechols, and to propose our vision for the future development of this field.

The synthesis of α-alkylidene cyclic carbonates (αCCs) by carboxylative coupling of CO2 with propargylic alcohols is receiving increasing interest but requires the use of catalysts that are most often added in large quantity and/or are lacking of selectivity. Herein, we describe that the fine-tuning of the structure of organocatalysts of the ammonium-type enables to identify the important structural parameters that dictate their catalytic performance. Tetrabutylammonium oxalate revealed to be one of the most attractive organocatalysts with a remarkable fast, complete and selective production of αCCs at low catalyst loading (2.5 mol%) under solvent free-conditions. This study clearly opens new avenues for the facile and selective synthesis of libraries of αCCs from CO2 and propargylic alcohol by using simple organocatalysts.

This review is dedicated to the state-of-the art routes used for the synthesis of CO2-based (a)cyclic carbonates and polycarbonates from alcohol substrates, with an emphasis on their respective main advantages and limitations. The first section reviews the synthesis of organic carbonates such as dialkyl carbonates or cyclic carbonates from the carbonation of alcohols. Many different synthetic strategies have been reported (dehydrative condensation, the alkylation route, the “leaving group” strategy, the carbodiimide route, the protected alcohols route, etc.) with various substrates (mono-alcohols, diols, allyl alcohols, halohydrins, propargylic alcohols, etc.). The second section reviews the formation of polycarbonates via the direct copolymerization of CO2 with diols, as well as the ring-opening polymerization route. Finally, polycondensation processes involving CO2-based dimethyl and diphenyl carbonates with aliphatic and aromatic diols are described.

Hierarchical porous N-doped carbon (NPC) is prepared by pyrolysis of poly(methyl methacrylate) (PMMA) particles decorated by graphene oxide (GO) and polypyrrole (PPy) as precursors and used as anode for lithium-ion batteries. The composite precursors with different diameter and composition (PMMA/GO/PPy-A and B) were conveniently prepared by dispersion polymerization of methyl methacrylate in the presence of graphene oxide as stabilizer in aqueous medium, followed by addition of pyrrole and its oxidative polymerization. After pyrolysis, the resulting NPC composites with hierarchically structured macro- and mesopores exhibit high surface area (289–398 m2/g) and different N-doping levels (7.46 and 4.22 wt% of nitrogen content). The NPC with the highest N-doping level (7.46 wt%) shows high reversible capacities of 831 mAh/g at 74.4 mA/g (C/5) after 50 cycles and excellent rate performances.