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Bio- and CO2-based high performance thermoset poly(hydroxyurethane) (PHU) glues were designed from solvent- and isocyanate-free formulations based on cyclocarbonated soybean oil, diamines (aliphatic, cycloaliphatic or aromatic) and functional silica or ZnO fillers. Shear strength values and cohesive or adhesive failure of glues were correlated with the crosslinking, mechanical and thermal properties of the nanocomposite PHU thermosets. The addition of SiO2 or ZnO fillers bearing cyclic carbonate groups at their surface enabled strong improvement in the adhesion performances of the glues up to 173% compared to the unfilled PHUs. The most performing reinforced PHU adhesives showed a shear strength up to 11.3 MPa for an aluminum substrate, and 10.1 MPa for stainless steel with cohesive failure. This study highlights that bio-based nanocomposite PHU thermosets are promising sustainable alternatives to conventional glues made of toxic formulations containing isocyanates.

Well-defined poly(lactide)-based block copolymers were synthesized by a heterogeneous solvent and metal-free green approach by using organocatalysts in supercritical carbon dioxide (scCO2). We first report on the homopolymerization of both l - and d , l -lactide by organocatalyzed Ring-Opening Polymerization (o-ROP) by using a bicomponent organocatalyst composed of a thiourea derivative and various tertiary amines as cocatalysts. Control over the molar mass and dispersity is achieved until high monomer conversion although the polylactides are insoluble in the polymerization medium. The precision synthesis of PLA-based block copolymers from various CO2-phobic hydroxyl end-capped macroinitiators such as polyethylene glycol, polycaprolactone, polybutylene succinate and polyphosphoester was then reported. Merging scCO2 with this organocatalytic system provides therefore a unique tool for the design under solvent-free conditions of poly(lactide)-based block copolymers that are insoluble in scCO2.

Access to well-defined polymers made of the so-called ‘Less Activated Monomers’ (LAMs) via controlled radical polymerization has long been a challenge due to the lack of radical stabilizing group on the double bond of these monomers. This Feature Article summarizes substantial progress in the organometallic-mediated radical polymerization (OMRP) of this important class of monomers including vinyl esters, olefins, vinyl chloride, vinyl amides, or ionic-liquid vinyl monomers. It aims to provide a clear and comprehensive account of the fundamentals and challenges in the OMRP of LAMs as well as an overview of the resulting macromolecular engineering opportunities. The input of photochemistry, environmentally friendly solvents or flow reactors in OMRP is also presented. Finally, it emphasizes how some well-defined LAMs-based materials contributed to the development of specific applications notably in the fields of biomedicine or energy.

This paper presents the work carried out within the European project RENAISSANCE-ITN, which was dedicated to the development of innovative polyelectrolytes for energy and environmental applications. Within the project different types of innovative polyelectrolytes were synthesized such as poly(ionic liquid)s coming from renewable or natural ions, thiazolium cations, catechol functionalities or from a new generation of cheap deep eutectic monomers. Further, macromolecular architectures such as new poly(ionic liquid) block copolymers and new (semi)conducting polymer/polyelectrolyte complexes were also developed. As the final goal, the application of these innovative polymers in energy and the environment was investigated. Important advances in energy storage technologies included the development of new carbonaceous materials, new lignin/conducting polymer biopolymer electrodes, new iongels and single-ion conducting polymer electrolytes for supercapacitors and batteries and new poly(ionic liquid) binders for batteries. On the other hand, the use of innovative polyelectrolytes in sustainable environmental technologies led to the development of new liquid and dry water, new materials for water cleaning technologies such as flocculants, oil absorbers, new recyclable organocatalyst platforms and new multifunctional polymer coatings with antifouling and antimicrobial properties. All in all this paper demonstrates the potential of poly(ionic liquid)s for high-value applications in energy and enviromental areas. © 2017 Society of Chemical Industry

Drug-eluting sutures represent the next generation of surgical sutures since they fulfill their mechanical functions but also deliver the drug in their vicinity after implantation. These implants are produced by a variety of manufacturing processes. Drug-eluting sutures represent the next generation of surgical sutures since they fulfill their mechanical functions but also deliver the drug in their vicinity after implantation. These implants are produced by a variety of manufacturing processes. Two general approaches can be followed: (i) the ones that add the API into the material during the manufacturing process of the suture and (ii) the ones that load the API to an already manufactured suture. Areas covered: This review provides an overview of the current manufacturing processes for drug-eluting suture production and discusses their benefits and drawbacks depending on the type of drugs. The mechanical properties and the drug delivery profile of drug-eluting sutures are highlighted since these implants must fulfill both criteria. Expert opinion: For limited drug contents, melt extrusion and electrospinning are the emerging processes since the drug is added during the suture manufacture process. Advantageously, the drug release profile can be tuned by controlling the processing parameters specific to each process and the composition of the drug-containing polymer. If high drug content is targeted, the coating or grafting of a drug layer on a pre-manufactured suture allows for preservation of the tensile strength requirements of the suture.

In polyjet printing photopolymer droplets are deposited on a build tray, leveled off by a roller and cured by UV light. This technique is attractive to fabricate heterogeneous architectures combining compliant and stiff constituents. Considering the layer-by-layer nature, interfaces between different photopolymers can be formed either before or after UV curing. We analyzed the properties of interfaces in 3D printed composites combining experiments with computer simulations. To investigate photopolymer blending, we characterized the mechanical properties of the so-called digital materials, obtained by mixing compliant and stiff voxels according to different volume fractions. We then used nanoindentation to measure the spatial variation in mechanical properties across bimaterial interfaces at the micrometer level. Finally, to characterize the impact of finite-size interfaces, we fabricated and tested composites having compliant and stiff layers alternating along different directions. We found that interfaces formed by deposition after curing were sharp whereas those formed before curing showed blending of the two materials over a length scale bigger than individual droplet size. We found structural and functional differences of the layered composites depending on the printing orientation and corresponding interface characteristics, which influenced deformation mechanisms. With the wide dissemination of 3D printing techniques, our results should be considered in the development of architectured materials with tailored interfaces between building blocks.

International audience; We have explored the domino reaction between propargylic alcohols, carbon dioxide and various alcohols with the double objective to prepare oxo-alkylcarbonates with a high yield and selectivity under mild conditions and to extend the process to the synthesis of phosgene-free polycarbonates. We first searched for a common catalytic system that was highly selective for the two reactions involved in the domino process, i.e. the cycloaddition of CO 2 to propargylic

In the recent decades, biodegradable and biocompatible polyphosphoesters (PPEs) have gained wide attention in the biomedical field as relevant substitutes for conventional aliphatic polyesters. These amorphous materials of low glass transition temperature offer promise for the design of soft scaffolds for tissue engineering. Advantageously, the easy variation of the nature of the lateral pendant groups of PPEs allows the insertion of pendent unsaturations valuable for their further cross-linking. In addition, varying the length of the pendent alkyl chains allows tuning their hydrophilicity. The present work aims at synthesizing PPE networks of well-defined hydrophilicity and mechanical properties. More precisely, we aimed at preparing degradable materials exhibiting identical hydrophilicity but different mechanical properties and vice versa. For that purpose, PPE copolymers were synthesized by ring-opening copolymerization of cyclic phosphate monomers bearing different pendent groups (e.g., methyl, butenyl, and butyl). After UV irradiation, a stable and well-defined cross-linked material is obtained with the mechanical property of the corresponding polymer films controlled by the composition of the starting PPE copolymer. The results demonstrate that cross-linking density could be correlated with the mechanical properties, swelling behavior, and degradation rate of the polymers network. The polymers were compatible to human skin fibroblast cells and did not exhibit significant cytotoxicity up to 0.5 mg mL-1. In addition, degradation products appeared nontoxic to skin fibroblast cells and showed their potential as promising scaffolds for tissue engineering.

We report organic radical functionalized graphite nanoplatelet (GNP) via a simple click reaction of the polymer propagated radical, polyvinylimidazolium functionalized with redox-active free radical TEMPO pendants groups. 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 CNO bond of the alkoxyamine pendant groups was thermally cleaved releasing the redox-active TEMPO nitroxide radicals. This simple and efficient strategy to synthesize graphite-functionalized PILs will provide new opportunities to fabricate many other polymer composite electrodes for desired electrochemical performance.

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.

Since the discovery of polyurethanes (PU) by Otto Bayer in 1937, PU hydrogels are still commonly produced by the polyaddition of nasty and toxic polyisocyanates with polyols in organic solvents or ...

Simultaneous condensation of aromatic aldehydes (ArxCHO; x = 1–4) on chitosan biopolymer (CS) affords, after water-evaporation, structurally-conjugated aryl-functionalized CS-Arx-f films. Similarly, cooperative assembly of two-dimensional nanometric graphene oxide (GO), aromatic aldehyde and chitosan provides transparent, flexible and crack-free aldehyde-functionalized, ternary-reinforced CS-Arx-GO-f nanocomposite films. Homogenous films were obtained using ortho-hydroxybenzaldehyde Ar1 while the para-hydroxybenzaldehyde Ar4 was prone to packing inside. Textural and mechanical properties were investigated and expectedly, significant improvement was found for CS-Ar1-GO-f because of the great dispersion of the aromatic and the presence of the filler. The sensitivity of unsaturated C N imine bond to hydrolysis was explored for triggering controlled release of aromatics from the as-prepared films. All of them were found to induce a time-dependent aromatic release. It has been moreover observed that the release was significantly delayed in CS-Arx-GO-f compared to CS-Arx-f, a fact attributed to the interplay of the ring with the basal and edges of graphene oxide, through π-π stacking and additional hydrogen bonding interactions. This finding shows that beyond the conventional wisdom using fillers for improving thermal and mechanical properties, the tiny carbon sheets can act as a regulator for aldehyde release, thereby providing a way for more controlled chemical delivery from confined nanocomposites.

In the last few years, polycarbonates have been identified as alternatives to poly(ethylene oxide) as polymer electrolytes for lithium battery applications. In this work, we show the design of CO2-sourced polycarbonates for their use in room temperature operating lithium batteries. Novel functional polycarbonates with alternating oxo-carbonate moieties and polyethylene oxide segments are synthesized by the facile room temperature (rt) organocatalyzed polyaddition of CO2-sourced bis(aalkylidene carbonate)s (bis-aCCs) with polyethylene oxide diols. The effect of the molar mass of olyethylene oxide on the ionic conductivity and thermal properties of poly(oxo-carbonate)s is investigated. The best candidate shows a low glass transition temperature of 44 C and a high ionic conductivity of 3.75 10 5 S cm 1 at rt when loaded with 30 wt% bis(trifluoromethanesulfonyl)imide salt (LiTFSI) without any solvent. An all-solid semi-interpenetrated network polymer electrolyte (SIN-SPE) is then fabricated by UV cross-linking of a mixture containing specifically designed poly(oxo-carbonate) bearing methacrylate pendants, diethylene glycol diacrylate and the previously described poly(oxocarbonate) containing LiTFSI. The resulting self-standing membrane exhibits a high oxidation stability up to 5 V (vs. Li/Li+), an ionic conductivity of 1.1 10 5 S cm 1 at rt (10 4 S cm 1 at 60 C) and promising mechanical properties. Assembled in a half cell configuration with LiFePO4 (LFP) as the cathode and lithium as the anode, the all-solid cell delivers a discharge capacity of 161 mA h g 1 at 0.1C and 60 C, which is very close to the theoretical capacity of LFP (170 mA h g 1). Also, a stable reversible cycling capacity over 400 cycles with a high coulombic efficiency of 99% is noted at 1C. Similar results are obtained at rt provided that 10 wt% tetraglyme as a plasticizer was added to the SIN-SPE. -Fonds National pour la Recherche Scientifique” (F.R.S.-FNRS) -Fonds Wetenschappelijk Onderzoek– Vlaanderen (FWO) -EOS project no. 019618F (ID EOS: 30902231). - CESAM Research Unit. - European Research Council by Starting Grant Innovative Polymers for Energy Storage (iPes) 306250 -Basque Government through ETORTEK Energigune 2013 and IT 999-16. - Spanish Ministry of Education, Culture and Sport for the predoctoral FPU fellowship received

The cobalt-mediated radical polymerization (CMRP) of new ionic liquid monomers (ILMs), vinyl imidazolium functionalized with redox-active free radical 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)VIm and its CMR copolymerization with vinyl imidazolium units functionalized with triethylene oxide (TEG)VIm produced a well-defined PILs (co)polymers. The controlled nature of (co)polymerization can be seen from the linear first-order kinetic plot, linear evolutions of the molar mass with total monomer conversion and the low polydispersity of the resulting (co)polymers. By combining the redox activity of (TEMPO)PVIm and remarkable ionic conductivity of (TEG)PVIm, outstanding rate capability performance was achieved with a remarkable capacity of 69 mAh g−1 at 60C. The obtained organic electrode can serve as sustainable electrodes in lithium ion batteries.

International audience; Gene transfection with polymeric carrier remains a challenge, particularly high transfection levels combined with low toxicity are hard to achieve. We herein revisit polyvinylamines, an old and neglected family of cationic polymers. They can be readily obtained by controlled hydrolysis of polyvinylamides prepared through (controlled) radical polymerization. A series of tailor-made and well-defined polyvinylamines bearing primary amino groups, and poly(N-methylvinylamine) bearing secondary amines, were evaluated for the transfection of cells with pDNA as a function of their molar mass, molar mass distribution and degree of deacetylation. Unexpected high transfection levels, in combination with low cytotoxicity were recorded for both series. Surprisingly, a great impact of the molar mass was observed for the primary amine polyvinylamine series, whereas the results were mostly independent on molar mass or dispersity for the polymer bearing secondary amine. It was further established that a certain percentage of acetamide groups increased the transfection level, while maintaining low cytotoxicity. These results highlight for the first time the real potential of polyvinylamines as gene carriers, and make these polymers very attractive for further development in gene therapy.

Herein, we developed a straightforward aqueous synthesis of unprecedented alternating peptide-peptoid copolymers via a Ugi four-component reaction applied to dipeptides. Functional peptide-peptoid copolymers as well as block copolymers were produced in a single step in the presence of acrylic acid and carboxylic acid-terminated poly(ethylene glycol). The thermoresponsiveness of these polymers is highlighted.

Polydimethylsiloxanes (PDMSs) bearing photoreactive coumarin groups have been synthesized by amidation of a coumarin acid chloride derivative with various amine-functionalized PDMSs. Upon exposure to UV light having a wavelength of above 300 nm, multifunctional coumarin-PDMSs are transformed into covalent networks via [2 + 2] photocycloaddition of two coumarin moieties forming a cyclobutane ring. Taking advantage of the possible localized irradiation through a photomask, a novel concept to generate patterned PDMS films with various surface topologies was demonstrated. This concept is based on the combination of a low molar mass difunctional PDMS with a multifunctional PDMS of a high molar mass forming a photoreversible network allowing osmotic diffusion of a linear PDMS-coumarin of low molecular weight in a loosely crosslinked network. Advantageously, illumination by a light source at 254 nm induces the photocleavage of the cyclobutane cross-links offering some photo-induced reversibility to the PDMS network. These novel photo-responsive networks are interesting for several applications, in photo-adaptable biomedical implants (particularly photo-adjustable intra-ocular lenses), photo-tuneable patterned microsystems (e.g. for microfluidics) and photo-switchable controlled release systems.

Polymer micelles have emerged as promising carriers for controlled release applications, however, several limitations of micelle-based drug delivery have also been reported. To address these issues, we have synthesized a functional biodegradable and cytocompatible block copolymer based on methoxypoly(ethyleneglycol)-b-poly(ε-caprolactone-co-α-azido-ε-caprolactone) (mPEG-b-poly(εCL-co-αN3εCL)) as a precursor of reduction sensitive core-crosslinked micelles. The synthesized polymer was formulated as micelles using a dialysis method and loaded with the anti-inflammatory and anti-cancer drug methotrexate (MTX). The micellar cores were subsequently crosslinked at their pendant azides by a redox-responsive bis(alkyne). The size distributions and morphology of the polymer micelles were assessed using dynamic light scattering (DLS) and transmission electron microscopy, and drug release assays were performed under simplified (serum free) physiological and reductive conditions. Cellular uptake studies in human breast cancer cells were performed using Oregon-green loaded core-crosslinked micelles. The MTX-loaded core-crosslinked micelles were assessed for their effects on metabolic activity in human breast cancer (MCF-7) cells by evaluating the reduction of the dye MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. The apoptosis inducing potential of MTX-loaded core-crosslinked micelles was analysed using Hoechst/propidium iodide (PI) and annexin-V/PI assays. The data from these experiments indicated that drug release from these cross-linked micelles can be controlled and that the redox-responsive micelles are more effective carriers for MTX than non-crosslinked analogues and the free drug in the cell-lines tested.

The aim of this study was to evaluate hot-melt extrusion (HME) as a continuous process to form cyclodextrin (CD) inclusion complexes in order to increase the solubility and dissolution rate of itraconazole (ITZ), a class II model drug molecule of the Biopharmaceutics Classification System. Different CD derivatives were tested in a 1:1 (CD:ITZ) molar ratio to obtain CD ternary inclusion complexes in the presence of a polymer, namely Soluplus® (SOL). The CD used in this series of experiments were β-cyclodextrin (βCD), hydroxypropyl-β-cyclodextrin (HPβCD) with degrees of substitution of 0.63 and 0.87, randomly methylated β-cyclodextrin (Rameb®), sulfobutylether-β-cyclodextrin (Captisol®) and methyl-β-cyclodextrin (Crysmeb®). Rheology testing and mini extrusion using a conical twin screw mini extruder were performed to test the processability of the different CD mixtures since CD are not thermoplastic. This allowed Captisol® and Crysmeb® to be discarded from the study due to their high impact on the viscosity of the SOL/ITZ mixture. The remaining CD were processed by HME in an 18mm twin screw extruder. Saturation concentration measurements confirmed the enhancement of solubility of ITZ for the four CD formulations. Biphasic dissolution tests indicated that all four formulations had faster release profiles compared to the SOL/ITZ solid dispersion. Formulations of HPβCD 0.63 and Rameb® even reached 95% of ITZ released in both phases after 1h. The formulations were characterized using thermal differential scanning calorimetry and attenuated total reflectance infra-red analysis. These analyses confirmed that the increased release profile was due to the formation of ternary inclusion complexes.

The design of functional 3D macroporous monoliths has become a necessity for a wide range of applications. The traditional post-modification strategies of porous materials are efficient but often consist of tedious multi-step processes. This work describes a straightforward macromolecular surfactant-assisted method for producing chemically functionalized macroporous polyHIPEs with interconnected structures. Accordingly, high internal phase emulsion-templated polymerizations were implemented in the presence of SG1-terminated amphiphilic copolymers prepared by nitroxide-mediated radical polymerization (NMP). The latter served as both stabilizers and functionalizing agents upon thermal activation of its terminal alkoxyamine and covalent anchoring of the released radical copolymer onto the walls of the scaffold. The effect of the polymerization temperature on the functionalization and openness of the final porous materials was explored. As a result, a range of open-cell styrene and acrylate-based polyHIPEs chemically grafted with PEO were obtained. Moreover, polyHIPEs were also decorated with alkyne-bearing PEO and subsequently modified via CuAAc click chemistry in order to demonstrate the potential of this macromolecular surfactant-assisted functionalization method.

A new photo-sensitive diblock copolymer composed of a hydrophilic sequence of poly(ethylene oxide) (PEO) linked to a CO2-philic sequence of poly(1H,1H,2H,2H-heptadecafluorodecyl acrylate) (PFDA) by a light sensitive o-nitrobenzyl group was successfully synthesized by RAFT polymerization and used as a stabilizer for the free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) dispersion in α,α,α-trifluorotoluene and supercritical carbon dioxide (scCO2). Thanks to this fluorinated stabilizer, well-defined particles of PHEMA down to 350 nm diameter were produced in scCO2. Advantageously, the photocleavable group at the block junction of the stabilizer could be cleaved by exposing the particles to UV light so that the fluorinated block could be extracted in TFT or scCO2. As supported by X-ray photoelectron spectroscopy (XPS) analysis, up to 80% of the fluorinated block of the stabilizer can be removed, leading to efficient swelling and dispersion of the resulting PHEMA nanogels in water.

Poly(hydroxyurethane) (PHU) thermosets reinforced with (functional) nanofillers were developed to design high performance adhesives for bare aluminum. Solvent-free cyclic carbonate/amine/PDMS formulations loaded with native, epoxy- or cyclic carbonate-functionalized ZnO nanofillers were premixed before deposition and thermal curing onto Al. The results highlight that the addition of PDMS prevents PHUs from delamination of the Al surface by increasing the adhesive hydrophobicity and thus limiting the water uptake. The dispersion of functional fillers within PHUs improves their thermal and mechanical properties. Benchmarking of the adhesive performances of the reinforced PHU glues with existing PHU formulations attests the benefits of dispersing functional fillers and PDMS within a resin and evidences a 270% increase of the shear strength of reinforced PHU adhesives compared to formulations reported in the literature.

Hydrogels based on polyurethane (PU) are promising (bio-) materials because of their biocompatibility, biodegradation and excellent mechanical properties. In this publication, polyurethane hydrogels were produced for the first time by a non-isocyanate route by solvent-free step-growth copolymerization between a CO2-sourced hydrophilic polyethylene glycol bi-cyclic carbonate with diamines in the presence of a cross-linker. Kinetic of poly(hydroxyurethane) (PHU) synthesis was monitored by ATR-IR and the chemical cross-linking was confirmed by rheology and gel contents measurements. Hydrogels were obtained by immersion of PHUs in water and the influence of the diamine/cross-linker ratio and the nature of diamine on the water swelling and compression properties (compression modulus, strain and stress at break) of PHU hydrogels was evaluated. Additionally, the compression properties of the hydrogels were improved by the addition of Montmorillonite as nanofiller in the PHU formulation. This work opens new application fields for CO2-sourced PHUs.

Combining the redox activity and remarkable adhesion propensity of polyphenols (such as catechol or pyrogallol) with the numerous tunable properties of poly(ionic liquid)s (PILs) is an attractive route to design inventive multifunctional macromolecular platforms. In this contribution, we describe the first synthesis of a novel family of structurally well-defined PILs functionalized with catechol/pyrogallol/phenol pendants by organometallic-mediated radical polymerization (OMRP) using an alkyl–cobalt(III) complex as initiator and mediating agent. The living character of the chains is also exploited to produce di- and triblock PILs, and the facile counteranion exchange reactions afforded a library of PILs-bearing free phenol/catechol/pyrogallol moieties. Electrochemical investigations of catechol/pyrogallol-derived PILs in aqueous medium demonstrated the characteristic catechol to o-quinone transformations, whereas, quasi-reversible doping/undoping with supporting electrolyte cations (Li+/tetrabutylammonium...

Polymers with repeating phosphoester linkages in the backbone are biodegradable materials that emerge as a promising class of novel biomaterials, especially in the field of drug delivery systems. In contrast to aliphatic polyesters, the pentavalency of the phosphorus atom offers a large diversity of structures and as a consequence a wide range of properties for these materials. In this paper, it is focused on the synthesis of well-defined polyphosphoesters (PPEs) by organocatalyzed ring-opening polymerization, improving the functionalities by combination with click reactions, degradation of functional PPEs and their cytotoxicity, and inputs for applications in drug delivery.

The synthesis of a series of poly(ethylene oxide)- b -polystyrene copolymers with different block lengths was performed by radical addition fragmentation chain transfer. These amphiphilic copolymers were tested as stabilizers for water-in-oil medium internal phase emulsion (MIPE) templating polymerization and the formation of polyMIPEs with controlled morphology. Aside from the structure of the emulsion stabilizer, several parameters susceptible to influence the size of the cavities and the interconnectivity of the porous monoliths were probed including the choice of the comonomers, treatment of the emulsion by ultrasound, the use of controlled radical polymerization method for the network formation as well as interfacial initiation. Interconnected cellular monoliths were produced. The polymerization of the ultrasonicated water-in-ethylhexylacrylate/divinylbenzene MIPE notably led to near-mesoporous open-cell material. Mechanical properties and specific surface areas of the polyMIPEs were also investigated and discussed.

The polymerization of cyclic phosphates to poly(phosphoester)s, PPEs, is optimized for chip-based microreactors under continuous flow conditions. The anionic ring-opening polymerization of 2-isobutyoxy-2-oxo-1,3,2-dioxaphospholane (iBP) via the use of two organocatalytic systems allowed to polymerize to nearly quantitative monomer conversion within 10 or 3 min, respectively at a reaction temperature of 40 °C. Further, the optimized polymerization protocol was applied to 2-butenoxy-2-oxo-1,3,2-dioxaphospholane (BP) which yields a polymer that carries an alkene functionality per monomer repeating unit. This material can be postmodified in an UV-induced radical thiol–ene reaction, which was also shown to proceed with very high efficiency under UV-flow conditions. Eventually, both reactions were coupled in a two-stage reactor setup, showing that the thermally-activated polymerization can be coupled with high efficiency to the UV-activated post-polymerization modification reaction. The introduced reactor setup can in the future be used to produce and screen a broad variety of functional PPE materials with various functionalities and physical properties.

Fully bio- and CO2-sourced non-isocyanate polyurethanes (NIPUs) were synthesized by reaction of carbonated soybean oil (CSBO) either with biobased short diamines or amino-telechelic oligoamides derived from fatty acids to achieve respectively thermoset or thermoplastic NIPUs. Biobased carbonated vegetable oils were first obtained by metal-free coupling reactions of CO2 with epoxidized soybean oils under supercritical conditions (120 °C, 100 bar) before complete characterization by FTIR, 1H NMR, and electrospray ionization mass spectroscopy (ESI-MS). In a second step, biobased NIPUs were produced by melt-blending of the so-produced cyclocarbonated oil with the biobased aminated derivatives. The thermal and mechanical properties of resulting polymers were found to be depending on the cyclocarbonated vegetable oil/amine ratio. More precisely, short diamines and CSBO led to the formation of cross-linked NIPUs, and the resulting tensile and thermal properties were poor. In contrast, elastomeric NIPUs derived f...

Chemical crosslinking is an efficient tool to improve or impart new properties to conventional polymers. Especially, crosslinking imparts remarkable shape–memory properties to poly-e-caprolactone (PCL) materials. Nevertheless, the processing of networks is often tricky due to infusibility and insolubility of cross-linked chains. Therefore, the synthesis of PCL networks including thermo-reversible crosslinks based on (retro)-Diels-Alder (DA) reaction were developed to allow preserving the melt-processing while keeping the required mechanical properties below the melting point. This paper aims at studying in depth, such thermo-dependent network formation and stability. Besides conventional swelling experiments, Raman spectroscopy was revealed as a powerful tool to follow the formation of the DA adduct during the crosslinking. In combination with rheological measurements, we were able to determine the most appropriate temperatures to form the network (DA crosslinking) and to process it (retro-DA reaction) without degradation of the material.

The performances of titanium dioxide (TiO2) thin films used in photoelectrochemical applications (solar cells, water splitting, photocatalysis, etc) highly depend on their morphology and interface. In this work, we describe a straightforward strategy for designing conductive carbon-coated TiO2 porous layers allowing for the tuning of interfacial charge transfers. Increased specific surface and improved conductivity are expected from the porosity and the carbon coating, respectively. In practice, polystyrene/polyacrylonitrile (PS-PAN) and polystyrene/polydopamine (PS-PDA) core-shell particles synthesized by emulsion polymerization are considered as templating agents for the production of carbon-coated and ordered porous TiO2 layers. After spin coating deposition of the particles, infiltration of the TiO2 precursor and calcination, voids are created in the film by thermal degradation of the PS cores whereas PAN and PDA produced carbon at the surface of the TiO2 inverse opal matrix. Uncoated PS particles are also considered as benchmark templating agents. Size and composition of the polymer particles as well as the morphology and electronic properties of the corresponding porous TiO2 films are evaluated. In particular, the charge transfer resistance of the films is investigated via Electrochemical Impedance Spectroscopy (EIS) as a preliminary assessment of these unprecedented carbon-coated porous TiO2 layers as semiconducting materials.

Photochemically cross-linked shape-memory polymer (SMP) materials have been achieved by functionalizing chain-ends of star-shaped poly(ϵ-caprolactone) (PCL) with 7-hydroxypropoxy-4-methylcoumarin followed by photodimerization of these end-groups. The kinetics of the network formation in function of the photosensitizer concentration has been studied by swelling experiments and rheology. Thanks to the design of a dedicated homemade mold, highly reproducible irradiation conditions have been achieved allowing to study the network formation and properties, especially the shape-memory properties, in relation to the coumarin dimerization degree as determined by Raman spectroscopy. In optimized conditions, PCL-based SMP materials exhibiting high fixity and recovery have been achieved in remarkably short irradiation time, typically 5 min. In addition, the precise control of the network cross-link density with the irradiation time, so as the high stability of the formed networks toward temperature variations was also demonstrated allowing the fine-tuning of the network properties by the irradiation process. Finally, the reversible character of the coumarin dimerization under light irradiation of appropriate wavelength has been quantified by Raman spectroscopy. The dimer photocleavage allows the photoreconfiguration of the networks offering the ability to modify the "permanent" shape of the SMP material, while preserving the excellent shape-memory properties.

The performance of lithium and sodium ion batteries relies notably on the accessibility to carbon electrodes of controllable porous structure and chemical composition. This work reports a facile synthesis of well-defined porous N-doped carbons (NPCs) using a poly(ionic liquid) (PIL) as precursor, and graphene oxide (GO)-stabilized poly(methyl methacrylate) (PMMA) nanoparticles as sacrificial template. The GO-stabilized PMMA nanoparticles were first prepared and then decorated by a thin PIL coating before carbonization. The resulting NPCs reached a satisfactory specific surface area of up to 561 m2/g and a hierarchically meso- and macroporous structure while keeping a nitrogen content of 2.6 wt %. Such NPCs delivered a high reversible charge/discharge capacity of 1013 mA h/g over 200 cycles at 0.4 A/g for lithium ion batteries (LIBs), and showed a good capacity of 204 mA h/g over 100 cycles at 0.1 A/g for sodium ion batteries (SIBs)., Comment: 14 pages, 9 figures

The synthesis of aliphatic polyesters by the ring-opening polymerization of cyclic monoesters was discovered by Carothers in the 1930s. Since then, a plethora of catalysts and initiators have been discovered to promote this polymerization. Nowadays, steadily increasing attention is paid to organocatalysts and, among them, acids, bases, and H-bond donors and acceptors. Organocatalysts today available for the polymerization of medium size cyclic monoesters such as δ-valerolactone and ε-caprolactone will be reviewed. Special attention will be paid to dual catalysts capable of activating both the initiator and the monomer. The most efficient catalysts promote fast and selective ring-opening polymerization. The mechanism based either on ionic interactions, the establishment of H-bonds or nucleophilic activation will be discussed. The importance of ring size will be highlighted by the organocatalyzed polymerization of β-butyrolactone, γ-butyrolactone and pentadecalactone as a typical macrocyclic monoester.

Glioblastoma is the most frequent and aggressive primary malignant tumor of the central nervous system with a gloomy prognosis. Platinum derivatives and one among them, cisplatin, exhibited promising results when locally administered into the brain of glioblastoma bearing rats. Nanovectorization of anticancer agents through polymeric nanoparticles may even promote drug accumulation within cells, thus concentrating the drug efficiently at its target. Anchorage of gadolinium complexes on the corona of such smart drug delivery systems could further allow magnetic resonance imaging (MRI) monitoring of the nanoplatform biodistribution in the damaged parenchyma and its therapeutic benefit. For this purpose, a biocompatible amphiphilic triblock copolymer, made of degradable polyester and polycarbonate and bioeliminable polyethylene oxide (PEO), was synthesized by successive ring-opening polymerizations. After micellization in water, gadolinium complexes were grafted onto the PEO micelle corona and the carboxylate functions, located at the surface of the micelle's core, were able to cross-link with Pt(ii) complexes. A macromolecular prodrug was therefore recovered in which more than one third of the carboxylate functions were linked to a platinum atom. By this strategy, stable cisplatin cross-linked nanoparticles were formulated with a mean size in the range of 100.63 ± 12.04 nm consistent with biological investigations. Relaxometry measurements both in water and in plasma at 7 T, 25 °C, confirmed the intrinsic potential of these hybrid nanoparticles as alternative MRI contrast agents with a substantial increase in the r2/r1 ratio by a factor of 3.3 and 2.7, respectively, compared to the conventional low molar mass Gd-DTPA. As a result, their infusion within the striatum of glioblastoma-bearing mice resulted in a hypersignal on T2-weighted MR images that persisted over time. Ultimately, the formulated prodrug exhibited up to 50-fold increased accumulation in human glioblastoma cell lines and up to 32-fold enhanced subsequent Pt-DNA adduct formation in comparison with free cisplatin, thus supporting the potential of this innovative bimodal tool for further applications.

Sulindac loaded poly(HEMA) cross-linked microparticles were synthesized via one-pot free-radical dispersion polymerisation in supercritical carbon dioxide (scCO2) in presence of photocleavable diblock stabilisers based on polyethylene oxide (PEO) and poly(heptadecafluorodecyl acrylate) (PFDA) bearing a o-nitrobenzyl photosensitive junction (hv) (PEO-hv-PFDA), and ethylene glycol dimethacrylate (EGDMA) as cross-linker. Poly(HEMA) cross-linked microparticles either empty or sulindac loaded were obtained with well-defined spherical morphology with the sizes between 250 and 350 nm. Additionally, upon UV-photolysis the stabiliser on the surface was cleaved which permits to microparticles to be redispersed in water leading to water swollen microgels about 2.1–3.6 µm. Moreover, the release behaviour from obtained microgels indicated the sustained release of sulindac over 10 days. Besides, the surface modification after UV-photolysis was studied and proved that the particles can be functionalised with further chemistries.

Cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) is successfully achieved in supercritical carbon dioxide (scCO2). CMRP of VAc is conducted using an alkyl-cobalt(III) adduct that is soluble in scCO2. Kinetics studies coupled to visual observations of the polymerization medium highlight that the melt viscosity and PVAc molar mass (Mn) are key parameters that affect the CMRP in scCO2. It is noticed that CMRP is controlled for Mn up to 10 000 g mol(-1), but loss of control is progressively observed for higher molar masses when PVAc precipitates in the polymerization medium. Low molar mass PVAc macroinitiator, prepared by CMRP in scCO2, is then successfully used to initiate the acrylonitrile polymerization. PVAc-b-PAN block copolymer is collected as a free flowing powder at the end of the process although the dispersity of the copolymer increases with the reaction time. Although optimization is required to decrease the dispersity of the polymer formed, this CMRP process opens new perspectives for macromolecular engineering in scCO2 without the utilization of fluorinated comonomers or organic solvents.

The solubility of ketoprofen and aspirin in subcritical and supercritical CO2 was measured using FTIR absorption spectroscopy in the large range of temperature of 298.2–353.2 K and pressure of 5–35 MPa. The evolution of the solubility of both active pharmaceutical ingredients (APIs) was fitted using the Chrastil’s equation. In addition, the speciation of both APIs in monomeric and dimeric forms was explored by analyzing the characteristic carbonyl stretching vibrations of the carboxylic acid functions assigned to the dimers and monomers, respectively. Moreover, the evolution of the dimerization constant K of the two drugs as a function of the temperature and the pressure of scCO2 has been reported.

International audience; Nanogels of controlled kinetic chain length were synthesized by cobalt-mediated radical cross-linking copolymerization (CMRccP) involving a vinyl monomer and a divinyl cross-linker. This strategy was first validated to achieve neutral poly(vinyl acetate) nanogels by CMRccP of vinyl acetate and divinyl adipate as a cross-linker at 40 degrees C in the presence of an alkyl-cobalt(III) serving both as an initiator and a controlling agent using ethyl acetate as a solvent. Poly(ionic liquid) nanogels were then directly obtained by CMRccP of N-vinyl-3-ethyl imidazolium bromide in the presence of 1,13-divinyl-3-decyl diimidazolium bromide as a cross-linker. CMRccP experiments could be conducted either in an organic solvent using dimethyl formamide or, more interestingly, in aqueous solution, demonstrating the robustness and versatility of this one-step process. Chain extensions of PIL nanogels were also carried out in water, forming core-shell structures, thus opening new avenues in the design of functional nanogels.

Preparation of transparent and superhydrophobic coatings by co-deposition of an aqueous solution of an amphiphilic fluorinated block copolymer (FBC) with silica particles was developped. Spin-coating of this aqueous solution onto glass followed by an appropriate thermal treatment promotes the self-assembly of the hybrid material with the formation of superhydrophobic, robust and transparent coatings.

Poly(ethylene oxide)-b-polyphosphoester amphiphilic block copolymers are known to self-assemble into polymer micelles when dissolved in water. This work aims at reporting on the improvement of the stability of the micelles at high dilution by crosslinking the hydrophobic polyphosphoester micellar core. Typically, an unsaturated alkene side-chain was introduced onto the cyclic phosphate monomer according to a one-step reaction followed by its organocatalyzed polymerization initiated by a poly(ethylene oxide) macroinitiator. This strategy avoids the use of any organometallic compounds in order to facilitate the purification and meet the stringent requirements of biomedical applications. After self-assembly in water, the micelles were cross-linked by simple UV irradiation. These cross-linked micelles have then been loaded with doxorubicin to evaluate their potential as drug nanocarriers and monitor the impact of crosslinking on the release profile.

Bio- and CO2-sourced non-isocyanate polyurethane (NIPU) microcellular foams were prepared using supercritical carbon dioxide (scCO2) foaming technology. These low-density foams offer low thermal conductivity and have an impressive potential for use in insulating materials. They constitute attractive alternatives to conventional polyurethane foams. We investigated CO2's ability to synthesize the cyclic carbonates that are used in the preparation of NIPU by melt step-growth polymerization with a bio-sourced amino-telechelic oligoamide and for NIPU foaming. Our study shows that CO2 is not only sequestered in the material for long-term application, but is also valorized as a blowing agent in the production of NIPU foams. Such foams will contribute to energy conservation and savings by reducing CO2 emissions.

Using aminoglycoside antibiotics as drug models, it was shown that electrostatic complexes between hydrophilic drugs and oppositely charged double-hydrophilic block copolymers can form ordered mesophases. This phase behavior was evidenced by using poly(acrylic acid)-block-poly(ethylene oxide) block copolymers in the presence of silica precursors, and this allowed preparing drug-loaded mesoporous silica directly from the drug-polymer complexes. The novel synthetic strategy of the hybrid materials is highly efficient, avoiding waste and multistep processes; it also ensures optimal drug loading and provides pH-dependence of the drug release from the materials.

The allyl phosphoester group is shown to be a protecting group for the synthesis of anionic polyphosphodiesters. Our strategy relies on the synthesis of a cyclic phosphate monomer bearing a pendant allyl phosphoester group, its easy purification by fractional distillation, its organocatalyzed ring-opening polymerization by 1,8-diazobicyclo[5.4.0]undec-7-ene (DBU) and 1-[3,5-bis(trifluoromethyl)phenyl]-3-cyclohexyl-thiourea (TU). Finally, the deprotection of the allyl phosphoester group is carried out by reaction with sodium benzenethiolate in the absence of any detectable degradation. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2642–2648

To explore the effectiveness of monofluorinated isoindigo as an electron-deficient building block in push-pull conjugated polymers for organic solar cell applications, four low bandgap copolymers are effectively synthesized and characterized. The effects of fluorine introduction, thiophene spacer length and polymer molar mass on the general electro-optical polymer characteristics, thin film blend microstructure and electronic performance are investigated. Isoindigo monofluorination effectively improves the power conversion efficiency from 2.8 up to 5.0% upon molar mass optimization, without using any processing additives or post-treatments.

This work investigates key parameters of a straightforward macromolecular surfactant-assisted functionalization strategy of porous polymers produced by high internal phase emulsion (HIPE) polymeriz...

International audience; The organometallic-mediated radical polymerization (OMRP) of N-vinyl-3-alkylimidazolium-type monomers, featuring the bis(trifluoromethylsulfonyl)imide counter-anion (Tf2N-) in the presence of Co(acac)(2) as controlling agent, is reported. Polymerizations of monomers with methyl, ethyl, and butyl substituents are fast, reaching high monomer conversion in ethyl acetate as solvent at 30 degrees C, and afford structurally well-defined hydrophobic poly(ionic liquid)s (PILs) of N-vinyl type. Block copolymer synthesis is also achieved by sequential OMRP of N-vinyl-3-alkyldazolium salts carrying different alkyl chains and different counteranions (Tf2N- or Br-). These block copolymerizations are carried out at 30 degrees C, either under homogeneous solution in methanol or in a biphasic medium consisting of a mixture of ethyl acetate and water. Unprecedented PIL-b-PIL block copolymers are thus prepared under these conditions. However, anion exchange occurs at the early stage of the growth of the second block. Finally, diblock copolymers generated in the biphasic medium can be readily coupled by addition of isoprene, forming all PIL-based and symmetrical ABA-type triblock copolymers in a one-pot process. Such a direct block copolymerization method, involving vinylimidazolium monomers bearing different alkyl chains, thus opens new opportunities in the precision synthesis of all PIL-based block copolymers of tunable properties.

Composite Crosslinked nanofibrous membranes of chitosan, ethylene glycol diglycidyl ether (EGDE) and polyethylene oxide was successfully prepared with bead free morphology via electrospinning technique followed by heat mediated chemical crosslinking. Architectural stability of nanofiber mat in aqueous medium was achieved by chemical crosslinking of only 1% EGDE, and tensile strength tests revealed that increasing EGDE content has considerably enhance the elastic modulus of nanofibers. The structure, morphology and mechanical properties of nanofibers were characterized by Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and Instron machine, respectively. Skin fibroblasts and endothelial cells showed good attachment, proliferation and viability on crosslinked electrospun membranes. The results indicate a good biocompatibility and non-toxic nature of the resulted membrane.

Highly expanded nanocomposite foams of polypropylene and carbon nanotubes (PP/CNT) are formed using supercritical carbon dioxide (scCO2) technology. The foaming parameters (temperature, pressure) are investigated to establish their influence on the morphology of the resulting foams and their impact on the electrical conductivity. As promising electromagnetic-interference (EMI) absorbers, the EMI shielding performance of the foams is determined, and a preliminary relationship is established between foam morphology and the EMI shielding performance. The best candidates are highly expanded foams with a volume expansion of >25, containing 0.1 vol% CNTs; they are able to absorb more than 90% of the incident radiation between 25 and 40 GHz.

Antibody-based products constitute one of the most attractive biological molecules for diagnostic, medical imagery and therapeutic purposes with very few side effects. Their development has become a major priority of biotech and pharmaceutical industries. Recently, a growing number of modified antibody-based products have emerged including fragments, multi-specific and conjugate antibodies. In this study, using protein engineering, we have functionalized the anti-hen egg-white lysozyme (HEWL) camelid VHH antibody fragment (cAb-Lys3), by insertion into a solvent-exposed loop of the Bacillus licheniformis β-lactamase BlaP. We showed that the generated hybrid protein conserved its enzymatic activity while the displayed nanobody retains its ability to inhibit HEWL with a nanomolar affinity range. Then, we successfully implemented the functionalized cAb-Lys3 in enzyme-linked immunosorbent assay, potentiometric biosensor and drug screening assays. The hybrid protein was also expressed on the surface of phage particles and, in this context, was able to interact specifically with HEWL while the β-lactamase activity was used to monitor phage interactions. Finally, using thrombin-cleavage sites surrounding the permissive insertion site in the β-lactamase, we reported an expression system in which the nanobody can be easily separated from its carrier protein. Altogether, our study shows that insertion into the BlaP β-lactamase constitutes a suitable technology to functionalize nanobodies and allows the creation of versatile tools that can be used in innovative biotechnological assays.

This paper aims at exploring the scCO2 impregnation of three commonly implanted polymer sutures made of poly-l-lactide (PLLA), poly(ethylene terephthalate) (PET) and polypropylene (PP) with two anti-inflammatory drugs namely ketoprofen and aspirin. For all the investigated polymer/drug systems, the drug loading increases with temperature and pressure. It appears that two main criteria must be fulfilled by the polymer to achieve high drug loading: (i) a good affinity between the polymer and the drug and (ii) a high chain mobility to favor the diffusion of the drug into the matrix. As the investigated PLLA fulfills these two requirements, drug loading up to 32.5% with ketoprofen and 8.1% with aspirin has been achieved.