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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; 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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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.

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; 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.

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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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.

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.

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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.

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.

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.

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.

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.

Methyl methacrylate was copolymerized with propyl N,N-tetramethylbis(phosphonate)-bis(methylene)aminemethyl methacrylate (MAC3NP2). The thermal degradation and flammability of this modified poly(methyl methacrylate) (PMMA) were compared with those of pure PMMA using thermogravimetric analysis (TGA) and pyrolysis combustion flow calorimetry (PCFC). The morphology of char was investigated using scanning electron microscopy and the yield of phosphorus using energy-dispersive X-ray analysis. The gases evolved during degradation in TGA were analysed using Fourier transform infrared spectroscopy. The total heat release and heat release capacity of the reactively modified PMMA are reduced, as compared to pure PMMA. The modified PMMA presents a better thermal stability (above 290 °C) than pure PMMA and leads to an important char formation. A comparison among TGA, PCFC and the amount of phosphorus in the condensed phase gives useful information about the role of phosphorus in the flame retardancy of the copolymer. The result reveals the effect of phosphorus not only in the condensed phase but also in the vapour phase. Copyright © 2011 Society of Chemical Industry

We report the cationic ring-opening polymerization of 2-methyl-2-oxazoline (MOx) using bio-based initiator (GCTs). The functional initiator GCTs was prepared by tosylation of the corresponding alcohol: glycerol carbonate (GC). The termination stage of the polymerization was achieved in presence of KOH and the telechelic polyoxazoline carrying five-membered cyclic carbonate and oxazolium end groups (GC-POxium) was converted to ((HO)2-POx-OH) carrying α-diol and ω-hydroxyl groups. End-functionalized polyoxazolines (HO)2-POx-OH with Mn ranging from 4200 to 8400 g mol−1 were synthesized. According to GPC results, the polymerizations of MOx using GCTs and other initiator coming from 1,2-isopropylidene-glycerol (Solk-Ts) were compared. On the basis of FTIR and NMR spectroscopies, the chemical modification of end chains of polyoxazolines was investigated by two alternative synthetic routes. The isocyanate route is a postpolymerization urethanization. The nucleophilic reactivity of the α-diol and ω-hydroxyl groups of (HO)2-POx-OH was studied with functional isocyanate (TESPI). In the carbonate route, the electrophilic reactivity of α- and ω-end groups of GC-POxium were explored with amine. It was demonstrated that during the termination stage of the polymerization in presence of allylamine both urethane linker in α-end chain was synthesized and the ω-oxazolium group was converted into terminal amine. The carbonate route is an alternative to synthesize urethane without isocyanate. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4027–4035, 2010

International audience; The cationic ring-opening polymerization of 2-methyl-2-oxazoline (MOx) using iodine initiating system was reported. Uncolored polyoxazolines were produced in spite of the use of iodine initiator, well-known dye molecule. Low molecular weight asymmetric telechelic polyoxazolines carrying an acetylimine head group and an oxazolinium end group were synthesized, with a good control over the molecular weight. NMR and MALDI-Tof experiments allowed the full determination of the chemical structures of the produced poly(2-methyl-2-oxazoline)s, notably with the acetylimine head group, explained by spontaneous α-HI elimination. Finally, to our knowledge, we reported the first detailed mechanism of cationic ring-opening polymerization of 2-methyl-2-oxazoline in acetonitrile according to UV experiments. An ionic-type mechanism was involved with the dissociation of molecular iodine to active initiating species.

Peroxide-containing PDMS was synthesized according to a new pathway. Although hydrosilylation is one of the main reactions carried out in silicone chemistry, the catalysts used are very sensitive to the chemical nature of the reactants and remained inefficient to graft allylic peroxide. Radical catalyzed thiol-ene chemistry was involved for the first time to yield an initiator group containing polymer. The peroxide-grafted polysiloxane structure and decomposition were characterized using 1 H, 13 C and 29 Si NMR, FT-IR and Raman spectroscopies, SEC and DSC. These macroinitiators can be used to obtain polysiloxane able to undergo crosslinking.

International audience; The synthesis of amphiphilic lipid-polyoxazoline based on copolymers (CO-POxn) with narrow distribution has been achieved via cationic ring-opening polymerization of 2-methyl-2-oxazoline (MOx). Lipid-macroinitiator (COTs) was obtained from commercial castor oil (CO), widely renewable agricultural resource. CO-POxn with various length segments were synthesized from a macroinitiator COTs in order to investigate the effect of the length of the hydrophilic segment on the solution behavior of the nonionic polymer surfactants CO-POxn. The results showed that the critical micelle concentration rised with the increase of POx content and inversely surface tension decreased. The average size of aggregates of these structures suggested the formation of vesicles or nonspherical micelles. Star-shaped morphology of CO-POxn in solid state has also been observed using environmental scanning electron microscopy (ESEM). Addionally energy dispersive X-ray (EDX) analysis demonstrated the presence of POx block in the concentric stripes of the texture.

The free-radical cotelomerization of 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) with 1,1,2,2-tetrahydroperfluorodecyl acrylate (PFDA) in the presence of 2-mercaptoethanol was performed at 80 °C in acetonitrile. Hydroxy end-groups of the cotelomers were reacted with 2-isocyanatoethyl methacrylate to give macromonomers. The P(TMSPMA-stat-PFDA) cotelomers, containing fluoro and silane groups, were then grafted onto silica nanoparticles. Optimal grafting conditions were found with TMSPMA monomer alone in toluene at 110 °C. The structure of the modified silica was analyzed by FTIR and 29 Si solid-state NMR. The amount of grafted TMSPMA or P(TMSPMA-stat-PFDA) was calculated by thermogravimetric and elemental analyzes. The grafting yield increased with the copolymer/silica weight ratio until a maximum value of 2.26 μmol/m 2 .

International audience; Novel organic/inorganic hybrid material was synthesized from poly(acrylazapropyl-trimethoxysilane)-b-poly( Ne-trifluoroacetyl-L-lysine) (P(AAPTMS)-b-P(TLL)) block copolymer using the sol–gel process. The treatment with ammonia solution permitted the hydrolysis of both trifluoro acetyl and trimethoxysilyl groups of the hydride copolymer followed by the condensation of the silanol groups, leading to crosslinked copolymers. The resulting cross-linked hybrid material was characterized using FT-IR, 29Si NMR, DSC, TGA, and environmental scanning electron microscopy. These techniques evidenced that a siloxane network was obtained. Amphiphilic polypeptide/inorganic hybrid copolymers were achieved and selforganized as particles in water.

10 pages; International audience; The telomerization of 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) in the presence of 2-mercaptoethanol was investigated at 80 C in acetonitrile. In our case, the efficiency of 2-mercaptoethanol as telogen agent, with TMSPMA, was demonstrated and the transfer constant (CT) was determined. Moreover, cotelomerization of TMSPMA with perfluorodecylacrylate (PFDA) using various PFDA contents was investigated in order to obtain a-hydroxy oligomers with statistical copolymer-type main chains bearing trimethoxysilyl and perfluoro pendant chains. Until 10 mol% PFDA, no phase separation occured. In this composition, rTMSPMA and rPFDA reactivity ratios were calculated, thus showing a tendency for a statistical distribution of the monomer units in the copolymer.

International audience; A new method to prepare ionomers bearing terminal ionic groups has been developed by modification of different hydroxyl terminated oligomers and using vinyl phosphonic acid as reagent. The different oligomers have been characterized by NMR, MALDI-TOF, SAXS, SEM-EDX, thermal analysis and their ionic crosslinking was achieved using different cations. Characterization of the network was performed and proved that an efficacious crosslinking was reached depending on the nature of the cations.

International audience; Glycolysates coming from the chemical recycling of PET scraps are most often very crystalline compounds making them difficult to perform in further reactions like step growth polyaddition with diisocyanates to obtain polyurethanes. The glycolysis of PET was investigated using unusual reagents: polyesters based oligomers, bisphenol A, cycloaliphatic alcohol and aliphatic diols. The thermal properties of the glycolysates obtained were compared in terms of crystallinity with that of coming from the glycolysis with DEG. The crystallinity extents were calculated using X-ray diffraction. Surprisingly, the crystalline or non-crystalline nature of the reactants do not predict the morphology of the final glycolysates.

New phosphonated cross-linked polymers were synthesized from telomers obtained by reaction between 10-undecenol and dialkyl hydrogenphosphonates. Telomers were studied using MALDI-TOF MS. It was proven that side products were produced, corresponding to cross-esterification reactions of dialkyl hydrogenphosphonate on telomers and to radical additions of telomer on 10-undecenol. The same behavior was also observed with allyl alcohol. Telomers were then converted to resins by methacrylation reactions. Finally, photopolymerization of the different resins synthesized was achieved and influence of the nature of the phosphonate group (diester, monoacid and diacid) was also evaluated.

Valorization of poly(ethylene terephthalate) (PET) waste has been achieved using glycolysis. The resulting diols were employed for the synthesis of triblock copolymers by atom transfer radical polymerization using copper (I) bromide and (1,1,4,7,10,10)-hexamethyltriethylenetetramine as catalyst system. Macroinitiator was obtained after depolymerization of PET waste followed by functionalization of the obtained glycolysate with 2-bromoisobutyrate bromide. Polymerization of styrene (S) and glycidyl methacrylate (GMA) has been achieved leading to PS-b-PETG-b-PS and (PS-stat-PGMA)-b-PETG-b-(PS-stat-PGMA) triblock copolymers. Best results were obtained at 100 °C. At this temperature, termination reaction were negligible and the measured number-average molar mass of the product increased linearly with monomer conversion in agreement with the theoretical Mn with low polydispersity products achieved. Polymers were also characterized by 1H NMR. This work presents a original valorization of PET waste as (PS-stat-PGMA)-b-PETG-b-(PS-stat-PGMA) copolymer could be used as heat curable coatings. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 433–443, 2008

The synthesis of macromonomers of acrylic acid was performed by telo- merization in a three-step process. The first step was the telomerization of tert-butyl acrylate in the presence of thioglycolic acid. Different molecular weights were obtained with different ratios of the monomer to the transfer agent. Good control of the molecular weights and architectures of the oligomers (e.g., the presence of an acid function on the chain end) was observed. The transfer constant of tert-butyl acrylate with thioglycolic acid was assessed (chain-transfer constant ¼ 0.6). In the second step, the terminal unsaturation of the oligomers was obtained by the reaction of the terminal acid groups with 2-isocyanatoethyl methacrylate to yield the macromono- mers of tert-butyl acrylate. In the last step, the tert-butyl acrylate groups were hydro- lyzed in the presence of trifluoroacetic acid at room temperature. The macromono- mers were copolymerized with styrene to obtain graft copolymers, and the reactivity ratios were evaluated. Finally, the copolymers were characterized with surface elec- tron microscopy and atom force microscopy. V C 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 395-415, 2007

Mono- and di-(trimethylammonium)-terminated polystyrenes with similar molar masses were synthesized. Bromopolystyrenes were first prepared by atom transfer radical polymerization (ATRP) using (N-Boc-propylamino)-2-bromoisobutyrate as initiator and Cu(I)Br/2,2'-bipyridine as catalytic system in bulk at 110 °C. α,ω-Telechelic polymer with double molecular weight with respect to the starting polystyrene was then obtained under atom transfer radical coupling process using 2,2/-bipyridine and copper(0) mediated reductive conditions in anisole. Final (trimethylammonium)-terminated polystyrenes were eventually obtained after removal of the tert-butyloxycarbonyl group and permethylation reactions. Intermediate and final polymers were characterized by 1 H NMR. The aligning properties of the obtained polymers for liquid crystals have been investigated. Pretilt and zenithal anchorings on ITO/glass substrates were measured. Finally, the possibility for the telechelic polystyrene to form a network in an inverted microemulsion was also considered.

National audience; The synthesis and characterization of photopolymerizable unsaturated polyester resins based on PET waste are described. The resins came from a depolymerization process based on the glycolysis of PET by diethylene glycol (DEG). Different molecular weights of glycolysates were synthesized. Then, the latter was functionalized by a methyl hemiester of maleic acid to obtain unsatured ,-bismaleate PET oligomers. In the presence of an electron donor monomer, such as triethylene glycol divinyl ether, these electron acceptor oligomers were copolymerized by way of charge-transfer complexes under UV irradiation. The reaction was monitored in situ by real-time IR spectroscopy to study the kinetics of photopolymerization. This one was studied in relation with the physical and chemical characteristics of oligoesters and the composition of mixtures containing divinyl ethers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1324-1335, 2007

We report a new kind of coating using UV waterborne technique with a biobased poly(amino acid) resin. Firstly we performed the thermal polycondensation of l-lysine during 15 h at 150 °C to synthesize water-soluble oligomers of poly-l-lysine (PLL) with 5–6 monomer units. These oligomers were then transformed in mild conditions to give photocurable water-soluble resins. We grafted on the poly-l-lysine backbone, allyl and maleamic acid functional groups, with a grafting rate close to 65% thanks to allyl glycidyl ether and maleic anhydride respectively. The influence of the reaction time and the reagents ratio on the grafting rate was investigated. Hence, the donor/acceptor photopolymerization of the mixture of allyl ether-poly-l-lysine (PLL-g-AE) with maleamic acid-poly-l-lysine (PLL-g-MA) in aqueous solution gave yellow transparent films. The degree of conversion and other kinetic parameters have been studied and detailed. This work contributes to the development of materials based on renewable resources and cleaner processes. It opens a new pathway to both fundamental and applied-driven research. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 955–963

International audience; A series of well-defined poly(vinyl acetate)-b-poly(vinyl alcohol) (PVAc-b-PVA) amphiphilic diblock copolymers with different hydrophilic block sizes were synthesized by a combination of macromolecular design via the interchange of xanthates (MADIX) polymerization and copper-catalyzed Huisgen’s click reaction (CuAAC). Poly(vinyl acetate)s were first prepared by MADIX polymerization using new chain transfer agents bearing clickable moieties. After the hydrolysis of PVAc homopolymers under basic conditions, PVAc-b-PVA copolymers were synthesized using Huisgen’s reaction with copper catalysis. Then, the selfassembly in water of PVAc-b-PVA was studied by dynamic light scattering (DLS), static light scattering(SLS), pyrene fluorescence and isothermal titration calorimetry (ITC). The dependence between the hydrophilic chain length of the copolymer and the critical aggregation concentration (CAC) value has been proved. The three different methods of characterization showed similar results, the CAC increasing with hydrophilic block length. Additionally, ITC has proved to be a very valuable technique for the study of self-organization of amphiphilic copolymers.

International audience; Photosensitive amphiphilic linear polyoxazolines (CoumC 11-POx n) bearing alkyl chain decorated by a UV-active coumarin end group have been synthesized by cationic ring-opening polymerization (CROP). Using DLS and DOSY NMR experiments, their self-assemblies in water were compared with those of homologous photo-unreactiveamphiphilic polyoxazolines (C m-POx n). In both cases, spherical nanoparticles with D H-values around 10 nm were observed. The CoumC 11-POx n nanoparticles were illuminated upon 300 nm inducing the photo-dimerization of the coumarin units located in theinnercompartment of the nanoparticles. Finally, the pros and the cons of the photo-dimerization of linear copolymersrelated to the photo-crosslinking of graft copolymerswere discussed.

International audience; The polymerization of methyl methacrylate (MMA) initiated by 2,2'-azobis(isobutyronitrile) (AIBN) as radical initiator in the presence of iodine (I2) was studied at different temperatures (T = 70 C and 80 C). This process, called reverse iodine transfer polymerization (RITP), is based on the direct reaction of radicals with molecular iodine. RITP efficiently controls the molecular weight (determined by size exclusion chromatography, SEC) and the structure of the polymer chains (confirmed by 1H and 13C NMR spectroscopy). For instance, PMMA samples of Mn,SEC = 2300 g mol-1 and polydispersity index PDI = Mw/Mn = 1.5 (Mn,theoretical = 2300 g mol-1), Mn,SEC = 4600 g mol-1 and PDI = 1.6 (Mn,theoretical = 4700 g mol-1), Mn,SEC = 9600 g mol-1 and PDI = 1.6 (Mn,theoretical = 10 000 g mol-1), and Mn,SEC = 19 200 g mol-1 and PDI = 1.5 (Mn,theoretical = 18400 g mol-1) were successfully prepared by RITP. The polymerization was followed by on-line 1H NMR spectroscopy, and the conversion of iodine was followed by titration with a thiol (thioglycolic acid). It was shown by SEC, titration of iodine, gas chromatography, and NMR analyses that RITP was split into two different periods: a first "inhibition" period during which iodine is consumed to form very short -iodotelomers, and a second period where the polymerization follows the kinetics of a conventional free radical polymerization governed by degenerative chain transfer. The degenerative chain transfer constant was estimated to be Cex 2.6 at T = 80 C. Last, the iodine-end-capped structure of the polymers was demonstrated by different analytical techniques, and the iodine functionality of the PMMA chains was up to 95%.

Different acrylate oligomers were synthesized by atom transfer radical polymerization in the presence of a transfer agent and CuBr/1,1,4,7,10,10-hexamethyltriethylenetetramine. The functionality in bromine was determined by 1H NMR. These oligomers were coupled in the presence of Cu(0) and the ligand 2,2′-bipyridine. The coupling yield was determined by size exclusion chromatography and NMR analysis and depended on the nature of the monomer and not on the molecular weight. In other words, the preliminary functionalization of the brominated chain end with styrene increased the coupling yield. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2377-2394, 2005

The telomerization of dimethylaminoethyl methacrylate (DMAEMA) with mercaptoethanol initiated by 2,2′-azobisisobutyronitrile was first investigated at 70 °C and the influence of the type of solvent was studied. The results showed that well-defined telomers of DMAEMA could not be synthetized via telomerization of DMAEMA in water or water/acetonitrile mixture since the telomerization reaction is in competition with the nucleophilic addition of thiol onto the monomer. Transfer constants for mercaptoethanol in benzene and acetonitrile were determined by Mayo's and O'Brien's methods. The transfer constant obtained in acetonitrile (0,6) was higher than that obtained in benzene. This difference can be explained by the fact that the thiol was consumed by two reactions: nucleophilic addition and telomerization. The influence of solvents on the polymerization kinetics was enlightened. These results were applied to the synthesis of macromonomers of DMAEMA with isocyanatoethyl methacrylate (IEM). These macromonomers were copolymerized with styrene.

The telomerization of 10-undecenol with alkyl hydrogenphosphonate was studied in order to synthesize telomers of different molecular weights. The study showed that telomers from 10-undecenol could be obtained despite the fact that the double bond has a low reactivity. The kinetic constan Kp 2 /K Tc was determined to be 7 x 10 -4 l.mol -1 . s -1 at 135°C and the transfer constant C T was 0.057. These values are normal for a low activity telogen such as hydrogenphosphonate and for slightly reactive monomers like 10-undecenol.

The synthesis of novel methacrylic phosphonated surface-active monomer by an original method is described. The crucial stage is the telomerization of undec-10-enyl acetate with dialkyl (alkyl = methyl or ethyl) hydrogenphosphonate. The phosphonated acetate obtained is selectively hydrolysed to give dialkyl(11-hydroxyundecyl)phosphonate as a precursor. The alcohol function allows setting of methacrylic side, which is highly reactive in radical polymerization. Particularly, by mono-dealkylation of dimethyl phosphonate in a selective and quantitative way, the potassium iodide permits to get, at one stage, the expected salt of sodium methyl phosphonate. The new surface-active sodium methyl(11-methacryloyloxyundecyl)phosphonate is characterized by 1 H and 31 P NMR. Its critical micelle concentration evaluated by conductometry is 2.4 × 10 -2 mol . l -1 .

The telomerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) with 2-mercaptoethanol in acetonitrile shows that the telogen can react with the monomer by nucleophilic addition. It is to say that the tertiary amino group leads to mucleophilic addition rather than telomerization. The oligomers thus obtained were functionalized with 1-(isopropenylphenyl)-1,1-dimethylmethyl isocyanate (TMI) in anhydrous toluene to afford macromonomers. These macromonomers were copolymerized with styrene and the r 1 , r 2 ratio was determined according to Jaacks and Macret's methods. It was thereby demonstrated that the r 1 value for this type of monomer is close to zero.

Summary: Atom Transfer Radical Polymerization (ATRP) of styrene was carried out at 110 °C using various substituted 2-bromoisobutyrates as initiators and the homogeneous catalyst CuBr/1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA). Telechelic oligomers were obtained by coupling the bromo terminated polymers using Cu(0)/PMDETA catalyst at 90 °C. The products were characterized by 1H NMR and MALDI-TOF and some unsaturated polymer chains were observed. They could originate from either disproportionation reaction or dehydrohalogenation of halogen terminated oligomers during MALDI analysis. Using this method, polymers with hydroxy, acid, or ester end groups were synthesized in a range of molecular weights from 1 000 to 13 000 g · mol−1. Coupling efficiency was between 79 and 100%, depending on the structure of the initiator. Coupling reaction of substituted polystyrenes using Cu(0)/PMDETA system at 90 °C.

The Telomerization of methyl methacrylate with 2-aminoethanethiol hydrochloride initiated by 2,2'-azobisisobutyronitrile, was investigated in dimethylformamide (DMF). First, the peculiar behavior of 2-aminoethanethiol was highlighted because it behaves as a peculiar transfer agent; this is because its transfer constant (C T ) is weak compared with that of other thiols. The presence of the amine function greatly disturbs the free radical telomerization reaction. Telomerization was performed in the presence of hydrochloric acid (HCl) to protect the amine group. The transfer constant was strongly influenced by the acid and water concentration. This work emphasized that the nature of the solvent plays an important role in the determination of the transfer constant. Thus, the value of C T increased from 0.23 in DMF to 0.56 in the HCl/DMF mixture. The primary and secondary amines were recovered after the reaction. The functionality of the primary and secondary amines was measured by titration. The influence of the concentration of HCl on the resulting amine functionality was investigated. The acid presence prevents the formation of secondary amines, arising from Michael's reaction, on methyl methacrylate. Finally, these results were applied to the synthesis of amine-functionalized telomers with molecular masses of 2000 to 15,000 g/mol. The amine function was correlated with the decrease of R 0 ([telogen]/[monomer]).

The preparation of original telechelic bismaleate and bisfumarate polybutadienes and their thermal properties are presented. These functional oligomers were synthesized by the esterification of a hemiester of maleic anhydride and methanol or an ethyl hemiester fumarate with hydroxytelechelic polybutadiene (HTPBd) in 94 and 63% yields, respectively. The thermal and thermomechanical properties of the materials obtained from the radical copolymerization of these telechelic bismaleate and bisfumarate polybutadienes with hexane-1,6-dimethacrylate (HDDMA) were investigated and compared to those of a classic polyurethane (PU) resin prepared from HTPBd and hexamethylene diisocyanate. Calorimetry identified only one glass transition temperature of −75°C assigned to the polybutadienic backbone for all three resins, while a second transition at 48°C attributed to the methacrylate network and was noted by thermomechanical analysis. Both bismaleate and bisfumarate oligomers led to materials having a slightly better thermal stability than that of the PU resin. Thermomechanical analyses indicated that the elastic moduli of the materials achieved from bismaleate and bisfumarate oligomers are higher than that of the PU resin, whatever the temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 72–79, 2003

Polyethylene terephthalate (PET) was alcoholised with ethylene glycol to synthesize hydroxytelechelic oligomers of PET. On the other hand, commercial hydroxytelechelic polyϵ-caprolactone was modified in order to synthesize carboxytelechelic polyϵ-caprolactone. The chemical structure of the products was investigated by 1H NMR. Multiblock copolyesters were then synthesized by polyesterification of hydroxytelechelic PET and carboxytelechelic polyϵ-caprolactone oligomers, using several catalysts and different reaction conditions, which have been linked with the average molecular weight of the obtained block copolyesters. It appeared that residual distannoxane species coming from glycolysis step are best catalyst for polyesterification reaction. The chemical structure of the synthesized copolyesters was investigated by size exclusion chromatography and 1H NMR. The thermal and thermomechanical behavior of the synthesized copolyesters was investigated by differential scanning calorimetry and by dynamic mechanical analyses. The ester–ester interchange reaction between the two types of oligopolyesters has been enlightened and estimated taking in account the different reaction parameters. This side reaction led to the miscibility of the two phases of the oligomers, that can be explained by a random structure of the copolyester, and prevented to obtain multiblock copolymer.

The object of this study was the synthesis of thermoplastic elastomer compounds by direct copolyesterification of reactive oligomers of poly(ethylene terephthalate) (PET) and of poly(tetramethylene oxide) (PTMO). PET was glycolysed to synthetise hydroxytelechelic oligomers of PET. Commercially available hydroxytelechelic oligomer. The chemical structures of these oligomers were investigated by 1 H NMR and size exclusion chromatography. Multiblock poly(ester-ether) was then obtained by polyesterification of the hydroxytelechelic and carboxytelechelic oligomers, using different catalysts and different reaction conditions. The best stoichiometric ratio was determined to lead to the highest M n . The chemical structure of the synthesised poly(ester-ether) was investigated by size exclusion chromatography and 1 H NMR. The thermal and thermomechanical behaviour of the synthesises poly(ester-ether) was investigated by differential scanning calorimetry and by dynamic mechanical analysis, and showed a thermoplastic elastomer behaviour. This product could also be an interesting was of chemically recycling PET waste.

This article explores the use of a new relation correcting theoretical (DPn) with experimental values obtained in the dead-end polymerization of styrene with azocompound. The syntheses were realized for several starting initiator-to-monomer ratios (C0's); values comprised between 10 and 0.1%, and the experimental (DPn) were obtained by size exclusion chromatography. Concerning the theoretical (DPn), a new relation is proposed considering the loss of initiating radicals [I · ] used in primary termination and both stationary states of I · and M · (macromolecular radicals) introduced as Bamford. Finally, (DPn)cum, previously defined by us, is introduced to consider the monomer conversion during oligomerization. Our relation fit very well in a large range of C0's, contrary to the application of the usual Mayo rule, and a discussion of validity is proposed. Our model also allows the prediction of (DPn)cum in a large range of telechelic oligomers from 10 to 150. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 236–247, 2003

Dimethyl 2-methacryloxyethylphosphonate, its monosodium salt, and methyl 2-methacryloyloxyethylphosphonic acid were synthesized, characterized, and grafted onto low-density polyethylene (LDPE) powder under melt-processing conditions in a Rheocord batch mixer (Karlsruhe, Germany). We studied the graft copolymerization onto LDPE in the presence of free-radical initiators, benzoyl peroxide, and dicumyl peroxide, and we performed grafting onto ozone-pretreated LDPE without any free-radical initiator. Effects of reaction time, initiator concentration, and reaction temperature were studied. The possibility of modifying LDPE in the molten state with phosphonated methacrylates was clearly demonstrated. Graft copolymers were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, and water contact angles. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2011–2020, 2002