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Innovative well-defined acidic photopolymerizable phosphorus-based copolymers were prepared and tested in well-known dental applications to improve the adhesion of dental self-etch adhesives (SEAs). Thus, innovative diblock copolymers of dimethyl-(methacryloyloxy)ethyl phosphonate (DMAOyEP) and 2-hydroxyethyl methacrylate (HEMA) were first synthesized by RAFT polymerization using a dithioester chain transfer agent (CTA) and then modified. First blocks were prepared with good control over the molecular weights and low dispersities. They were then used as macro-chain transfer agents (macroCTAs) to control well the polymerization of a second block. Appropriate functionalization of the diblock copolymers was performed. First, the dithiobenzoate chain-end was removed, leading to the discoloration of the copolymers. Secondly, polymerizable groups were incorporated by a partial functionalization of the hydroxyl group of the HEMA moiety with 2-isocyanatoethyl methacrylate (IEMA). Finally, the acidic copolymers were obtained via the deprotection of phosphonated ester groups. Following this strategy, a range of copolymers was developed and compared, varying the percentage of polymerizable groups, block compositions, molecular weights and architecture. Even if the adhesion of dental self-etch adhesives (SEAs) is currently adequate, improvements are still welcomed, and these new phosphonic acid-based materials are an opportunity to develop new dental formulations. So, dental adhesive properties were evaluated with shear bond strength (SBS) experiments to highlight the best developed materials. This contribution shows the interest of employing appropriate polymerization techniques, and appropriate functionalization reactions to develop new materials that could improve the specific properties of dental formulations.

International audience; Lipidic polyols based on α‐hydroxyketone reactive groups were investigated for polyurethane thermosets. The reactivity of this peculiar secondary alcohol group in triacylglycerol structure was compared, without use of catalyst, to that of poly(1,2‐diol) triacylglycerol and castor oil to demonstrate the influence of ketone in the α position of the alcohol group in the presence of HDI for the urethanization rate. The kinetic effect of the ketone group was also studied on various lipidic architectures: mono(α‐hydroxyketone) ester, di(α‐hydroxyketone) diester and tri(α‐hydroxyketone) triacylglycerol. The presence of hydrogen bonds in the network coming from urethane, residual alcohol, and ketone in hard segments of PU was discussed and correlated with the thermal stability and the soft mechanical properties of the resulting polyurethane thermosets.

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International audience; Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) is functionalized via radical grafting with 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO) initiated using 2,5-Bis(tert-butylperoxy)-2,5-dimethylhexane. The existence of the epoxide group on the SEBS backbone is evidenced by 1H nuclear magnetic resonance. A size exclusion chromatography (SEC) study reveals some chain coupling, and this phenomenon is limited by controlling the quantities of peroxide and monomer reagents used during the radical grafting. Photo-crosslinking of SEBS-g-VCHO under ultraviolet irradiation in the presence of a cationic initiator is then successfully performed with resultant gel contents higher than 85%. Mechanical properties of SEBS and crosslinked materials are measured by tensile tests on thin films. On the one hand, those tests reveal a significant increase of Young's modulus of the crosslinked materials. On the other hand, the diminution of elongation at break is much more limited; crosslinked materials retain their elastomeric properties with an elongation at break greater than 200%. Finally, the photosensitive SEBS-g-VCHO is used to show the adhesion performance of the photo-crosslinking coating as well as a resin for the stereolithography process.

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National audience; Les élastomères thermoplastiques de la famille des copolymères poly(styrène-b-(éthylène-co-butylène)-b-styrène), dits SEBS, sont des matériaux de hautes performances en raison de leur microstructure particulière et de leur allongement à la rupture élevé. Ils sont largement utilisés comme matériaux absorbeurs de chocs, isolants de câbles ou dans des formulations d'adhésifs et de mastics. Ils présentent l’avantage de pouvoir être mis en œuvre par différents procédés (injection, extrusion, application en solution…).Bien que le SEBS soit largement utilisé aujourd'hui dans des applications de grande diffusion et des secteurs de pointe, seules quelques études se sont focalisées sur la modification du SEBS par greffage radicalaire du fait de sa sensibilité aux radicaux libres. Passaglia et Rosales ont rapporté en 2000 une dualité entre le degré de greffage d’un monomère comme l’anhydride maléïque et la β-scission, voire de réticulation des chaînes de SEBS [1,2]. Ces deux phénomènes conduisent à une dégradation très rapide des propriétés mécaniques du matériau et surtout de son allongement à la rupture. Aussi, accroître les applications potentielles du SEBS par modification de ses propriétés mécaniques reste un défi important.Dans cette étude, le SEBS a été fonctionnalisé par greffage radicalaire du 4-vinyl-1-cyclohexène 1,2-époxyde (VCHO), un monomère réactif par voie UV cationique grâce à son cycle époxyde cyclo-aliphatique. Ce greffage permet la réticulation ultérieure du SEBS sous rayonnement UV. À notre connaissance, c’est la première fois que la réactivité radicalaire du groupe vinyle du VCHO est mise en évidence, notamment par 1H-RMN, tout comme son greffage sur un polymère oléfinique. La photo-réticulation du SEBS-g-VCHO sous irradiation UV en présence d'un photoamorceur cationique a ensuite été conduite avec succès menant à des teneurs en gel supérieures à 85 %. Les propriétés mécaniques du SEBS-g-VCHO réticulé ont été caractérisées par des essais de traction sur films minces. Ces tests ont révélé une augmentation significative du module d'Young du SEBS-g-VCHO réticulé. Par ailleurs, les matériaux réticulés ont conservé leur comportement d’élastomères avec un allongement à la rupture supérieur à 200 %.Ces nouveaux matériaux pourraient donc être mis en œuvre pour la réalisation de revêtements ou de pièces obtenues en stéréolithographie 3D afin d’élargir la gamme d’élastomères réactifs actuellement utilisés dans ces applications.

We report herein a study on the alcohol-free, ring-opening polymerization of trimethylene carbonate (TMC) in THF, catalyzed by 1,5,7-triazabicyclo [4.4.0] ec-5-ene (TBD) with ratios nTBD/nTMC ranging between 1/20 and 1/400. In all cases, the reaction proceeds very rapidly, even faster than in the presence of alcohol initiators, and provides PTMC with molecular weights up to Mn = 34,000 g mol−1. Characterization of the obtained PTMC samples by MALDI-TOF mass spectrometry, triple detection size exclusion chromatography and 1H NMR spectroscopy reveals the presence of both linear and cyclic polymer chains.

International audience; Well‐defined linear alkyl benzene surfactants (COxn) were successfully synthesized using cardanol as a green phenolic alternative and initiator for polyoxazoline (POx), the hydrophilic block of nonionic surfactants. Various hydrophilic lipophilic balance values were investigated by varying the POx length according to the [monomer]/[initiator] ratio. The chemical structure of the surfactants, in particular the terminal groups, was well identified by matrix assisted laser desorption ionization time of flight mass spectrometry demonstrating the good progress of the cationic ring‐opening polymerization. The COxn surfactants spontaneously self‐assembled in water at a critical aggregation concentration of 1–2 µmol L−1 into nano‐objects characterized by a hydrodynamic diameter of 11–24 nm and a number of aggregations ranging from 30 to 60 according to the worm‐like micelle model.

International audience; Polymeric materials derived from fatty acids (FA)s were synthesized through free radical polymerization and evaluated as viscosity index improvers (VII) in an organic triglyceride lube oil (OTO). For this purpose, various FA-based copolymers were designed to own a reduced solubility at low temperature in OTO which can be gradually improved by increasing temperature. Different fatty amide methacrylates were chosen for their poorly oil-miscible repeating units while fatty ester methacrylates, 2-(methacryloyloxy)ethyl oleate (MAEO) and 2-(methacryloyloxy)ethyl 4-(dodecylthio)oleate (MAEOSC12), were used as oil-miscible comonomers for providing copolymers with a minimum of solubility in the lube oil. All copolymers were synthesized with a 50:50 M feed ratio and were fully characterized through 1H NMR, SEC, DSC, and TGA analyses. Then, rheological study of oil-copolymer blends revealed that copolymers containing –NH function were able to have a higher impact on oil viscosity at high than at low temperatures suggesting the coil copolymer expansion. This improvement of thickening power with temperature in OTO was further optimized by increasing the copolymer molecular weight, dispersity, concentration, pendant aliphatic chain length or by adding an additional aliphatic chain in the copolymer backbone. Moreover, copolymer additions in OTO did not disturb the initial Newtonian behavior of OTO at −30 °C which corresponds to the lube oil pour point.

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Sağır, Özlem (Balikesir Author), Introduction More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. Methods and analysis EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. Ethics and dissemination EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369. ©

International audience; Well-defined double hydrophilic block copolymers (DHBCs) of poly(ethylene glycol)-block-poly(N,N-diethyla-crylamide) (PEG-b-PDEAm) were synthesized via a reversible addition-fragmentation chain-transfer (RAFT) polymerization of N,N-diethylacrylamide (DEAm) using dithioester terminated PEG of different chain lengths as macro-chain transfer agents. Controlled molecular weight and narrow molecular weight distribution were achieved as proven by size exclusion chromatography (SEC). Cloud points (CP) were determined via turbidity measurements with ultraviolet-visible spectroscopy (UV-vis) and LCST by differential scanning micro-calori-metry (micro-DSC). They range from 32 to 40°C depending on the PDEAm length block and its concentration. Above the LCST, fluorescence spectroscopy and dynamic light scattering (DLS) demonstrated that the PEG-b-PDEAm copolymers self-organized into large aggregates. More interestingly, copolymers pre-aggregated at relatively high concentrations below the LCST.

International audience; Hydrophobically modified ethoxylated urethanes (HEURs) are associative polymers that, compare to others, are far less sensitive to solution parameters, especially pH and ionic strength. Therefore, they are widely used as rheology modifiers in many different waterborne systems such as inks, coatings, emulsions, etc. In solutions, HEURs form transient networks through molecular associations between their hydrophobic groups. The transient network formation and its characteristics are responsible for the rheological properties and depend on the HEUR chains architecture. Many parameters such as molecular weight, size and nature of hydrophobic groups, polymer concentration, etc must be controlled to tune the several physicochemical properties of HEUR solutions. This article aims to give an overview of the HEUR studies reported in the literature in order to highlight the structure/rheological properties relationship. The article also draws attention to new trends in HEURs with innovative architectures and stimuli-responsive properties.

International audience; To overcome the present limitations in the synthesis of biodegradable triblock copolymers with PLA as central building block, three different reactional mechanisms (coordination-insertion, anionic and cationic) have been involved, while employing the transition from organometallic to organic catalysis. Even though activated chain-end mechanism with stannous octanoate is well known for the successful ROP catalytic reactivity, the synthesis of PLA based triblock copolymers according to this route revealed not negligible transesterification reactions. In the same way, the activated chain-end mechanism through nucleophilic activation (TBD) presented either no reactivity or weak control over the anionic polymerization process. Herein, we therefore propose an activated monomer mechanism as general and simple route for obtaining controlled PTMC-b-PDLLA-b-PTMC and PCL-b-PDLLA-b-PCL triblock copolymers by using cationic organocatalysis (MSA). 1H, 13C-NMR and DOSY-NMR spectra confirmed the well-controlled polymer architecture of the B-A-B triblock copolymer.

International audience; This work describes the synthesis of alkyl sulfur‐functionalized polymethacrylate‐based Viscosity Index Improvers (VII) derived from oleic acid (OLA) for mineral paraffinic lubricating oils. In this strategy, OLA was first quantitatively ramified by alkyl thiols containing long aliphatic chains through thiol‐ene coupling as demonstrated by 1H NMR spectroscopy with the complete consumption of OLA internal double bonds. The resulting alkyl sulfur‐functionalized OLA‐based derivatives were methacrylated through Steglich esterification in order to afford highly suitable hydrophobic OLA‐based monomers which, as far as we know, have not been described yet in the current literature. High polymethacrylate molecular weights were reached through radical polymerization despite the long alkyl pendant chains contained in their backbones. Finally, the resulting alkyl sulfur‐functionalized OLA‐based polymethacrylates have been blended in a mineral paraffinic oil (MPO) of reference at 5 wt% and evaluated as VII. Rheological measurements revealed that polymer thickening powers were significantly improved in oil with temperature and promoted by increasing the pendant alkyl thiol contained in polymer backbones. Moreover, the viscosity index of MPO was significantly improved with the addition of both synthesized homopolymers which confirmed their efficiency as VII. In the meantime, these results have been compared with a previously reported polymer, the poly(2‐[methacryloyloxy]ethyl oleate) (PMAEO), which demonstrated a lower VII efficiency compared with its analogous polymethacrylates containing an additional alkyl chain in their pendant chains.

This work described the design of an efficient oleic‐acid based viscosity control additive for lubricating oils as potential alternative to petroleum poly(alkyl)methacrylates (PAMAs) additives. Hence, Poly(2‐(methacryloyloxy)ethyl oleate) (PMAEO) was synthesized by free radical homopolymerization to afford a comb‐like polymer structure similar to common PAMAs. Then, in order to evaluate its efficiency as viscosity control additive, the resulting polymer was mixed at several concentrations from 1%wt to 10%wt with different oil compositions, including a mineral paraffinic oil (MPO) and an organic triglyceride oil (OTO). For all polymer‐solution blends, relative viscosities (RV) measurements showed that addition of PMAEO in MPO had a better contribution on oil viscosity at 100°C than at 20°C (RV = 1.16 at 40°C while RV = 1.25 for 3%wt of PMAEO in MPO). These results were attributed to the coil expansion of polymer chains with increasing temperature. Additionally, rheological studies showed that addition of 3%wt of PMAEO in MPO improved the MPO cold flow properties at −30°C by decreasing the required yield stress to put the oil in motion from 310 mPa to 42 mPa. These results are in total accordance with the common viscosimetric properties of PAMAs‐based viscosity control additives at low and high temperature in mineral oils.

Background and objectives To assess lung ultrasound for the diagnosis and monitoring of respiratory complications in thoracic surgery. Methods Prospective observational study in a University hospital, single institution. Adult patients scheduled for pulmonary resection surgery excluding pneumonectomy. An ultrasound follow-up was performed from the day before the surgery to the third day after surgery with calculation of B-line and lung score (reaeration and loss of aeration scores). Respiratory complications were collected throughout the hospitalization period. Results Fifty-six patients were included. Eighteen patients presented a respiratory complication (32%), and they presented significantly higher BMI and ASA scores. Patients operated by videothoracoscopy were less at risk of complications. At day 3, a reaeration score ≤ 2 on the ventilated side or ≤ -2 on the operated side, and a B-line score > 6 on the operated side were in favor of a complication. Conclusion Lung ultrasound can help in the diagnosis of respiratory complications following pulmonary resection surgery.

International audience; Oligomers coming from glycerin carbonate acrylate (GCA) and solketal acrylate (SolA) were synthesized in good yields by free-radical chain transfer polymerization using 2-mercaptoethanol (ME) as chain transfer agent. These oligomers were totally soluble in solvents and did not exhibit branching or gelation. The efficiency of the chain transfer polymerization process on these glycerol-based acrylate monomers was demonstrated and reactive cotelomers bearing both acetal and cyclocarbonate groups were obtained. The structure of these oligomers was well-characterized by NMR, SEC, FTIR and MALDI-Tof spectroscopies. The oligo(GC-stat-Sol)s are particularly interesting, notably in terms of reactivity and solubility in various organic solvents and water that can be modulated by varying different SolA/GCA ratios. These results open the way to a widespread valorization of glycerol.

Photopolymerization is the subject of a growing interest both at industrial and academic levels because it provides high reaction kinetics, low emissions of volatile organic solvents and in some cases, low shrinking stress. This polymerization route has been largely developed using radical polymerization of vinyl monomers, but to a lesser extent by ring-opening polymerization (ROP). Beyond epoxides, which were the first monomers polymerized by a cationic ring-opening polymerization (CROP), the photopolymerization of other cyclic monomers has recently spread out thanks to the emergence of novel initiating systems. This review states an overview of the spectrum of cyclic monomers that have been polymerized by light-induced polymerization processes. In a first part, the photosensitive species able to trigger or to induce a change of kinetics of ROP reactions are presented according to their activation mechanism, i.e photouncaging, photoswitching or photoredox. In a subsequent part, the different monomer classes and their photopolymerization mechanisms are described with an emphasis on the properties of resulting materials. The last part covers the use of photoROP for several applications.

Vegetable oil-based microparticles were elaborated using environmentally friendly chemistry for pharmaceutical applications such as drug delivery systems. Castor oil (CO) was cross-linked by sol–gel chemistry to obtain a hybrid material offering original properties. CO functionalization was successfully achieved in the bulk with 3-isocyanatopropyltriethoxysilane (IPTES), then a simple and robust o/w emulsion process allowed both shaping functionalized oil into microparticles and favoring oil cross-linking. Several parameters were studied such as the stirring mode or the gelling agent for controlling microparticle characteristics. Spherical hybrid microparticles with a monodispersed size (around 300 μm) and a hybrid composition (13% w/w of mineral part) were characterized by size measurement, electronic microscopy, energy-dispersive X-ray spectroscopy, and thermal analysis. The effectiveness of the microparticles as potential drug delivery systems using ibuprofen as model molecule was demonstrated with a l...

International audience; Amphiphilic photo-induced triblock copolymers were successfully prepared by photodimerization of a photo-active initiator bearing coumarin moieties (CmTs2) before synthesizing, by cationic ring-opening polymerization (CROP), various lengths of polyoxazoline block. The DLS and TEM studies of the triblock copolymers self-assembly in water revealed that over 99% of the nanoparticles have a DH-value of 10 nm. The total photo-activity of the coumarin units permitted p-stacking interactions in the nanoparticle core and further its crystallization as demonstrated by DSC and X-ray diffractometry. An original nonspherical morphology of the nanoparticles resulted with an elongated shape.

International audience; The effects of polylactide-graft-cellulose nanocrystals on the thermal and mechanical properties of poly(l-lactide) matrices were investigated. Cellulose nanocrystals (CNCs) were grafted with polylactide chains via a solvent-free process by ring-opening polymerization of l-lactide using magnesium hydride as a catalyst. The efficiency of grafting was determined by infra-red, X-ray photoelectron spectroscopy and nuclear magnetic resonance analyses. X-ray diffraction analyses showed that the crystalline nature of the CNCs was preserved. Nanocomposites based on poly(l-lactide) matrix containing ungrafted nanocrystals (PLLA/CNCs) and grafted nanocrystals (PLLA/PLLA-g-CNCs) were investigated. DSC revealed that the grafted nanocrystals exhibited a strong influence on the crystallinity of the nanocomposites, inducing a significant enhancement of the mechanical properties of PLLA/PLLA-g-CNCs compared with PLLA/CNCs material. The role played by the polylactide grafted layer on the interaction between the CNCs and PLLA matrix was revealed by mechanical analyses in the solid and molten states.

A series of bio-based epoxidized plasticizers (CExEp) for soft PVC was synthesized from cardanol and various fatty acids by esterification and epoxidation of the fatty and cardanol unsaturations. The plasticizing properties of these additives for PVC films were proved considering thermal and mechanical data. They seem to be a potential bio-based alternative plasticizer to diisononyl phthalate (DINP), one of the most widespread phthalate plasticizers, with less rigid and stable films. The synergy between epoxy groups, cardanol ring and fatty chains to elaborate efficient primary plasticizers was demonstrated. Moreover, the eco-toxicity using daphnies, algae, and plants as model organisms and endocrinal disruptor tests (YES/YAS) were realized. Our results revealed that the fatty cardanol plasticizer causes a global decrease in toxicity compared to DINP and no harm for environment and human health were detected without endocrine perturbation effect. These positive results of toxicology allow to consider these cardanol plasticizers in industrial applications as alternative to DINP.

International audience; The modification of natural oils with heteroatoms leads to materials that can be employed in various areas thanks to their specific properties. Here, asolventless chemical modification of epoxidized linseed oil with an aminosilane without a catalyst is developed, and a detailed study of the chemicalreactions involved during the process is reported. The mechanism results in two competitive reactions: the ring-opening of epoxides and trans-amidification of triglycerides with the amine functional group of aminosilane. These competitive reactions are shown by infrared spectroscopy (FTIR) and 1H, 13C, and 2D nuclear magnetic resonance (NMR). Even if the epoxy ring-opening remains the major route, the trans-amidification cannot be ignored. These modified oils are very reactive under atmospheric conditions by cross-linking according to a polycondensation of the Si(OMe)3 moieties or via a sol-gel process and lead to a rapid hardening. The final material gives hydrophobic and glossy coatings on cellulose and glass.Practical Applications: This paper details the easy route to convert vegetable oils into coatings by crosslinking under mild conditions. These bio-based materials can be applied as oil-based impregnating products for exterior wood protection and in the hydrophobization of paper.

International audience

The increasing price of barrels of oil, global warming, and other environmental problems favor the use of renewable resources to replace the petroleum-based polymers used in various applications. Recently, fatty acids (FAs) and their derivatives have appeared among the most promising candidates to afford novel and innovative bio-based (co)polymers because of their ready availability, their low toxicity, and their high versatility. However, the current literature mostly focused on FA-based polymers prepared by condensation polymerization or oxypolymerization, while only a few works have been devoted to radical polymerization due to the low reactivity of FAs through radical process. Thus, the aim of this Review is to give an overview of (i) the most common synthetic pathways reported in the literature to provide suitable monomers from FAs and their derivatives for radical polymerization, (ii) the available radical processes to afford FA-based (co)polymers, and (iii) the different applications in which FA-based (co)polymers have been used since the past few years.

International audience; This study reports two routes for the synthesis of epoxidized oleic acid (OLA)‐based polymethacrylates. The first one consisted of the synthesis followed by epoxidation of the OLA‐based methacrylate, 2‐(methacryloyloxy)ethyl oleate (MAEO), prior to its radical polymerization. In the second pathway, MAEO was first homopolymerized to afford poly(2‐(methacryloyloxy)ethyl oleate) (PMAEO) and, then, the internal double bonds of the oleate were epoxidized at different yields ranging from 20% to 100%. All polymeric structures were confirmed using 1H nuclear magnetic resonance (NMR), and characterized through size‐exclusion chromatography (SEC), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) analyses. The resulting polymers were then blended at 5 wt.% in a mineral paraffinic oil (MPO) and in a biobased organic triacylglycerol oil (OTO) to be evaluated as viscosity index improvers (VII). The partially epoxidized polymers up to 40% were soluble in MPO. According to a rheological study, the oil‐soluble epoxidized polymers resulting from the epoxidation of PMAEO exhibited a much higher influence on oil viscosities at high temperatures than at low temperatures compared to the low‐epoxidized PMAEO molecular weight obtained by the first strategy. Additionally, the viscosity indices of both lubricating oils were significantly improved with the addition of the epoxidized OLA‐based polymers resulting from the epoxidation of PMAEO, which confirmed their efficiency as VII.

International audience; Hereby, a facile one step synthesis of polyoxazoline coated Superparamagnetic Iron Oxide Nanoparticles is reported. The functionalization efficiency is demonstrated using several complementary techniques including direct High Resolution-Transmission Electron Microscopy observations of the polyoxazoline layer. The hybrid nanoparticles have a spinel Fd-3 m structure, a mean particle size of around 12 nm and a high saturation magnetization of 72 emu/g.

The use of functional polymers for the sorption of metallic species in water was widely practiced in treatment processes. Such sorbents offered the possibility to remove a large range of metals because of the variety of possible functional groups on polymeric backbones. In particular, acidic groups (carboxylic, phosphonic or sulfonic groups) proved to be of great interest for the sorption of different cations. Sorption efficiency and selectivity through complexation or ion exchange interactions were directly linked to the nature of both the functional groups and the cationic metallic ions. In addition, the physical nature of materials was another important parameter that had to be considered. Depending on the polymer solubility, the cross-linking density, and the polymeric architecture, significant differences regarding sorption properties were observed in the sorption kinetics. Thus, it was challenging to select the appropriate polymeric sorbent with the most relevant physical nature and functionality in the area of wastewater treatment. This review aims at reporting organic polymeric materials bearing acidic groups able to interact (selectively or not) with metallic cations. Both synthetic and bio-based materials were reviewed and main parameters that had to be considered when choosing functional organic sorbents for the removal of metallic pollution were highlighted. Finally, recyclability of the polymeric sorbents was also considered.

In this work, partially biobased methacrylate polymers with various fatty acid side chains were used as efficient polymeric viscosity modifiers for mineral paraffinic oil (MPO). Firstly, oleic, palmitic, myristic and lauric acids were functionalized with 2-hydroxyethyl methacrylate by Steglich esterification to provide suitable monomers for radical polymerization. The resulting monomer from oleic acid (2-(methacryloyloxy)ethyl oleate) was polymerized through conventional radical polymerizations and telomerization in order to evaluate the influence of the polymer molecular weight on its efficiency as a viscosity modifier. Additionally, methacrylate monomers containing different chain lengths of fatty acids were involved in reversible addition–fragmentation chain transfer polymerization to obtain polymers with similar molecular weights in order to compare their efficiency as viscosity modifiers. For this purpose, all fatty acid-based polymers were mixed at 3 wt.% in MPO and relative viscosity measurement between MPO and polymer–MPO blends was performed at various temperatures. The results demonstrated that fatty acid-based methacrylate polymers have a higher polymer contribution on MPO viscosity with increasing temperature. This specific viscosimetric behavior was related to the coil polymer chains’ expansion with temperature, which was improved by increasing the polymer molar mass and the length of dangling fatty alkyl chains hanging off polymer backbones.

A novel route to prepare fluorinated grafted copolymers via the use of nitroxides and under mild conditions is described. First, iodine transfer polymerization of vinylidene fluoride (VDF) in the presence of 1-iodoperfluorohexane led to two PVDFs (average molar masses of 1700 and 4000 g mol−1 and dispersities of 1.2). Then, the grafting of nitroxide moieties onto PVDF backbone was achieved in solution without any polymer activation. The obtained PVDF-g-nitroxide polymers acted as efficient macroinitiators for the polymerization of styrene leading to PVDF-g-PS graft copolymers with styrene content ranging from 17 to 40 w.% and PS molar masses varying from 1000 to 1500 g mol−1. It was experimentally evidenced that the grafting took place from methylenic protons, especially from tail-to-tail addition, and theoretical calculations of bond dissociation energies confirmed such a finding. It was also demonstrated that the nature of the solvent had a great influence on the success of the grafting mechanism as the reaction was only efficient in N-methyl pyrrolidone. Considering the high chemical stability of PVDF, this chemical route paves the way towards the synthesis of various valuable graft copolymers.

Bio‐based plasticizers bearing moieties exhibiting flame retardancy properties [dimethyl (methyl oleate)phosphonate (PMO), diethyl (methyl oleate)phosphonate (PMO2), dimethyl (methyl linoleate)phosphonate (PML), dimethyl (dimethyl oleate)phosphonate (PDE)] are synthesized from methyl oleate, methyl linoleate, and oleic diacid through free‐radical addition of dialkyl phosphonates. Soft PVC is prepared from PMO, PMO2, PML, and PDE primary plasticizers and compared to materials containing usual diisononyl phthalate DINP. Rheological behavior, thermal stability, mechanical properties, and flame resistance performances of these PVC films are carefully investigated. The presence of the phosphonate group into the plasticizer structure explains the best thermal stability of the PVC films based on phosphonated plasticizer than that of based on DINP. Regarding all these results, PMO and PDE can be considered as efficient flame retardant primary plasticizers for PVC and can substitute phthalates in soft PVC based materials. Practical Applications: These biobased additives are elaborated as plasticizers for PVC improving flame retardancy. Lipids were investigated as additives for polymeric materials. Looking at replacing phthalates in soft PVC formulations, phosphonated lipids demonstrate both a flame‐retardant efficiency and plasticizing properties (mechanical properties, gelation temperature) for this polymer.

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An iodine modified polypropylene surface was synthesized by iodine plasma activation. The obtained polypropylene surface was found to be a useful platform for secondary reactions. For instance, an azide-functionalized PP was prepared by nucleophilic exchange reaction. The surface was proven to be reactive toward R group of an alkyne modified RAFT agent via the copper-catalyzed azide–alkyne cycloaddition. RAFT mediated graft polymerization of methacrylic acid was carried out and lead to a controlled polymerization from the surface. Characterizations of the modified surface and the grafted polymers were performed through FTIR-GATR, XPS, AFM and colorimetric assays.

Vegetable oil based hybrid films were developed thanks to a novel solvent- and heating-free method at the air-water interface using silylated castor oil cross-linked via a sol-gel reaction. To understand the mechanism of the hybrid film formation, the reaction kinetics was studied in detail by using complementary techniques: rheology, thermogravimetric analysis, and infrared spectroscopy. The mechanical properties of the final films were investigated using nano-indentation, whereas their structure was studied using a combination of wide-angle X-ray scattering, electron diffraction, and atomic force microscopy. We found that solid and transparent films form in 24 hours and, by changing the silica precursor to castor oil ratio, their mechanical properties are tunable in the MPa-range by about a factor of twenty. In addition to that, a possible optimization of the cross-linking reaction with different catalysts was explored, and finally cytotoxicity tests were performed on fibroblasts proving the absence of film toxicity. The results of this work pave the way to a straightforward synthesis of castor-oil films with tunable mechanical properties: hybrid films cross-linked at the air-water interface combine an easy and cheap spreading protocol with the features of their thermal history optimized for possible future micro/nano drug loading, thus representing excellent candidates for the replacement of non-environmentally friendly petroleum-based materials.

A series of amphiphilic photo-responsive heterografted copolymers have been successfully synthesized. The random copolymers were composed of a methacrylate backbone, with various compositions of hydrophilic oligomeric 2-methyl-2-oxazoline side chains (OMOx) and hydrophobic long alkyl chains terminated by a coumarin moiety (Cm). Using dynamic (DLS) and static light scattering (SLS), and transmission electron microscopy (TEM), their self-assembling behavior was studied in water using the nanoprecipitation method. Depending on the system, one, two or three particle size distributions co-exist in solution. However, DLS measurements showed that monomodal and slightly polydisperse self-assemblies were obtained with the more hydrophobic copolymers (i.e., 85% of hydrophobic monomers with a long alkyl chain terminated by a coumarin moiety (MCm) per molecule) with hydrodynamic diameters ranging from ca. 130 to 300 nm. Morphological information on these self-assembly structures was obtained using SLS: a Gaussian behavior has thus been evidenced. Finally, these heterografted copolymers were illuminated using UV light at λ = 350 nm inducing photo-crosslinking of the coumarin units. The influence of UV illumination on the thus-formed nanoparticles was investigated by carrying out complementarily DLS-measurements and UV spectroscopy.

Pyrolitic lignin was modified through two methods. First, it was grafted with polylactide chains via a solvent-free process by ring-opening polymerization of l -lactide using calcium hydride as a catalyst. The efficiency of grafting was determined by infra-red, nuclear magnetic resonance and time-of-flight secondary ion mass spectrometry analyses. Then, lignin particles were oxygen plasma-treated and immersed in l -lactide solution. Infra-red and X-ray photoelectron spectroscopy revealed that chains bearing ester groups similar to that of lactide were covalently grafted onto the lignin. Composite cast films based on poly( l -lactide) matrix containing ungrafted lignin (lignin/PLLA), chemically-grafted lignin copolymer (PLA- g -lignin/PLLA) and plasma-treated lignin (plasma-treated lignin/PLLA) were investigated. Differential scanning calorimetry and dynamical mechanical analyses revealed that plasma-treated lignin preserved the crystalline structure of PLLA matrix and had a significant reinforcing effect compared with lignin and PLA- g -lignin. Results were compared with literature data.

In this study, various organic compounds, with different activation modes, have been tested as catalysts for the ring-opening polymerization (ROP) of cyclic butylene terephthalate oligomers (CBT) in bulk at 210 °C, using tert-butylbenzyl alcohol (tBnOH) as initiator. Among them, 1,3,5-triazabicyclo[4.4.0]dec-5-ene (TBD) appeared to be the most efficient, achieving high monomer conversions in short reaction times (within minutes). Analysis by size-exclusion chromatography (SEC) of the poly(butylene terephthalate) (PBT) synthesized using this catalyst also showed that the polymerization follows the expected theoretical Mn trend for molecular weights up to 50 kg·mol−1. Chain-end fidelity relatively to the alcohol initiator has been confirmed by MALDI-TOF mass spectroscopy, which showed that all polymer chains possess the tert-butylbenzyl moiety as chain-end. Finally, to demonstrate the potential of this system for the synthesis of PBT-based block copolymers, a monomethyl ether poly(ethylene glycol) (PEG) of 5000 g·mol−1 has been employed as initiator for the ROP of CBT. A PEO-b-PBT block copolymer of 15,000 g·mol−1 could thus been obtained, as confirmed by the shift of the SEC traces towards higher molecular weights and the same diffusion coefficient determined for 1H NMR signals of the PEO block and the PBT block. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1611–1619

International audience; Photo-active nanoparticles (NPD, NPT, NPH) were elaborated in water from amphiphilic diblock (D), triblock (T) and heterograft (H) copolymers based on a chromatic unit, coumarin, linked to an alkyl chain and a hydrophilic polyoxazoline chain. Under UV-exposure, for graft copolymers, the coumarin moieties crosslink the nanoparticle core (NPHx) while a simple dimerization chain by chain happens with linear diblock and triblock copolymers (NPDx and NPT). The self-assembly of these copolymers was examined as well as the UV-activity and UV-reversibility of the corresponding NPs by UV spectroscopy. Their stability under light exposure and temperature was also monitored by dynamic light scattering (DLS). Finally, the loading of a lipophilic fluorescent probe (Nile Red) into the NP core was evaluated by fluorescence emission. All these data illustrate the tunable size, UV-activity, stability and loading efficiency of the NPs by the starting macromolecular architecture of the amphiphilic copolymers. Triblock copolymers seem to be a promising tool for switchable NPs characterized by two opposite states: NPs with and without photo-dimerized core alternatively.

To encapsulate and deliver poorly water-soluble drugs, castor oil/silica hybrid microparticles (HMP)s were synthesized. Green chemistries were used to silylate the oil and further cross-link it into solid microparticles by sol-gel reaction. Silylated castor oils (ICO)s at various silylation ratios were prepared and allowed the solubilization of ibuprofen at several concentrations up to 16 wt%. The HMPs were formulated by ThermoStabilized Emulsion (TSE) process which permits to “freeze” the oil-in-water emulsion while the sol-gel reaction occurs. The hybrid mineral/organic composition and the morphology (spherical shape and micrometric size) of these HMPs were determined by complementary technics (SEM, TGA, EDX, 29Si NMR and FTIR spectroscopies). The HMPs reached a good ibuprofen loading efficiency regardless to the formulation used while the release kinetics in simulated oral administration exhibited a tunable release during 3 h according to the silylation ratio. The ibuprofen rate also influenced its own amorphous or crystalline character within the HMPs. For subcutaneous conditions, ibuprofen release took place over 15 days. Finally, biodegradability assays in simulated digestion medium suggested a surface-limited hydrolysis of the particles and cytocompatibility studies on NIH-3T3 and Caco-2 cells demonstrated an excellent cellular viability.

Experimental conditions for the synthesis of poly(e-caprolatone)-graft-poly(vinyl alcohol) (PCL-g-PVA) and poly( l -lactide)-graft-poly(vinyl alcohol) (PLLA-g-PVA) via a PVA/MgH2 macroinitiator were optimized. Heat stability of PVA (99% hydrolyzed) in l -lactide (L-LA) melt was studied by DSC, TGA to lower the reaction temperature and time in order to avoid degradation. Thus, no degradation of copolymers occurred and 13C NMR study showed that l -lactide was incorporated in graft chains as isotactic poly( l -lactide) without racemisation for 140–160 °C, up to 25 h, L-LA/PVA ratio in the range 3–12. Such synthesis using non-toxic catalyst and reactants in a solvent-free medium can be described as environment-friendly. Amphiphilic behavior of copolymers was studied in aqueous solution according to their chemical structures: critical micelle concentration CMC (0.03–0.5 g L−1), average diameter of micelles (80–150 nm), surface tension γCMC (46–63 mN m−1), hydrophilic to lipophilic balance HLB (Griffin definition 4–7), and also from cast films: surface energy γs (36–50 mJ m−2). This environment-friendly process is suitable for the use of graft PVA copolymers in biomedical area for investigations under micelle applications.

International audience; The synthesis and the aggregation behavior of novel well-defined poly(N,N-diethylacrylamide)-b-poly- (L-lysine) (PDEAm-b-PLL) double hydrophilic block copolymers are reported. PDEAm-b-PLL was prepared using an original strategy which consisted of the ring opening polymerization (ROP) of N3- trifluoroacetyl-L-lysine N-carboxyanhydride using terminated-thiol PDEAm as a macroinitiator. After deprotection of the amine group of the L-lysine, pH- and thermo-sensitive poly(N,N-diethylacrylamide)- b-poly(L-lysine) block copolymers were obtained. The structure of the copolymers was characterized by 1H NMR and FT-IR. Then, pH and temperature sensitivities were measured by 1H NMR and UV/Vis spectroscopy. At different pH values and temperatures, poly(L-lysine) and poly(N,N-diethylacrylamide) showed typical behaviors, which led to different types of aggregation in aqueous solution. The influence of both stimuli was carefully investigated by DLS, TEM, and SANS.

International audience; The worldwide production of glycerin exceeds the demand from the chemical industry and new applications have been investigated these last years mainly in the area of additives. Here, water–soluble glycerin-based polyacrylates and polymethacrylates have been prepared by free-radical polymerization of solketal (meth)acrylate using various transfer agents derived from fatty chains. According to specific experimental conditions, linear functional oligomers were obtained. This versatile process allowed designing amphiphilic copolymers after the hydrolysis of acetal groups. These oligomers exhibit critical aggregation concentration values ranging from 5 to 15 × 10−6 mol.L−1 without any strong differences between polyacrylate and polymethacrylate series. In the case of glycerol-based polyacrylate derivatives, the observed monomodal populations can be ascribed to the low polydispersity indexes.

Polymeric materials, in particular PVC, can find various industrial utilizations thanks to the use of plasticizers added during their processing. The most famous applications include wires and cables, coatings, flooring, paintings, packaging… After some generalities concerning plasticization theories and the description of plasticized petro- and bio-based polymers, this review details the well-known different petro-based plasticizers and more particularly phthalates which represent the most important category of PVC plasticizers. Owing to migration problems, impact on the human health and the environment, alternative candidates have been developed by researchers. Renewable resources and their wastes offer a large platform for the design of bio-based plasticizers using polysaccharidic or lipidic structures. In an in-depth analysis, the bio-based plasticizer structures, their groups and substituents (ester groups, alkyl chains, aromatic rings…) are gathered and examined in order to be able to predict their plasticizing efficiency and design new molecular and macromolecular plasticizers from natural resources. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 11–33

International audience; Organomodified layered silicates and silicas have been incorporated in thermoplastic elastomers such as styrene-ethylene-butylene-styrene copolymers (SEBS) and polyurethanes (PU) in order to improve mechanical properties - especially tear strength. The organically modified layered silicates used were Cloisite (R) 30B, a montmorillonite modified with a ternary ammonium salt with hydroxyls as end groups and Nanofil (R) 2 which is organically modified by long chains of hydrocarbon and benzyl groups. Sepiolite, a natural clay with fibrous morphology was also used. The silicas incorporated are Aerosil 300, hydrophilic fumed silica and Aerosil R202, hydrophobic fumed silica. Nano-particles are incorporated between I and 5 weight percent. A compatibilizer SEBS grafted with maleic anhydride has been incorporated in some of the formulations for a better dispersion of some of the nano-particles. Different ways of incorporation have been investigated. For SEBS formulations, melt blends of SEBS pellets and clays have been prepared with an internal mixer and then films have been casted. For polyurethanes, solvent blending of polyols and clays were carried out in a vessel and then, compression molding of the blend with diisocyanates was made to synthesize polyurethanes. Materials have been compared on the basis of normalized tear test and sequenced tensile test. Mechanical parameters, as stabilization ratio (Mullins effect) and viscoelastic ratio, have been defined by integration of the stress-strain curves obtained. An interesting improvement of tear strength was observed for modified materials.