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The present work focuses on the preparation, using a solution process, of flexible conductive nanocomposites based on polyurethane (PU)/polyaniline (PANI) with different mass percentages: 2, 3 and 4%. Because of the low conductivity of the PU + PANI films, these later were doped with inorganic NiCl2. PU + PANI undoped films were synthesized by a “one-shot” process. For doping process, PANI has been doped according to two different methods: The first one consists of the impregnation of the pristine PU + PANI film in a solution of inorganic salt dopant with a solvent (THF) during a soaking time, while the second method uses a “one-shot” process. The structural characterization and conductivity properties of the polymer blends were examined by differential scanning calorimetry, Fourier transform infrared spectroscopy and dielectric measurements spectroscopy. The results show that NiCl2 significatively increases the conductivity compared to pure PU + PANI blends, with better results using the second method of synthesis.

In recent years, bacteriocins produced by lactic acid bacteria (LAB) have shown great potential for food safety preservation, especially for ready-to-eat products. In this study, bio-protective membrane was made from plasma-treated polypropylene film and functionalized with Carnobacterium divergens V41 (bacteriocin-producing strain) for the purpose of inhibiting Listeria monocytogenes growth in culture media and cold-smoked salmon (CSS) at refrigerated temperatures. In semi solid Brain Heart Infusion (BHI) agar, bio-protective plastic membrane led to a 3-Log reduction in L. monocytogenes count compared to the control, after 14 days of aerobic incubation at 8 °C. In vacuum-packed CSS, L. monocytogenes growth was inhibited by bio-protective plastic membrane after 7 days of storage at 4 °C and 21 days at 8 °C. Antilisterial activity of plastic membrane was even better than C. divergens cells added in CSS by direct spraying. Stability test has shown that bio-protective plastic membrane stored for 42 days at 4 °C still exerted antimicrobial activity against L. monocytogenes on BHI agar (2-Log reduction compared to the control). These preliminary results demonstrate that bio-protective plastic membrane can be used to control pathogenic bacteria in food products with potential industrial development.

This report is the first one on a cationic waterborne polyurethane (cWPU) latex based on epoxidized hydroxyl telechelic natural rubber (eHTNR) polyol, providing potential for use as a coating made of renewable resources. A cWPU latex was synthesized by step growth emulsion polymerization from hydroxyl telechelic natural rubber (HTNR with M n = 3000 g.mol―1) with fixed N-methyl diethanol amine content of 5.6 wt% and 2,4-toluene diisocyanate (NCO index = 100). The effects of proportion of epoxide units on HTNR polyol from 0 to 30 % on preparing cWPU latex were investigated. Chemical structures of HTNR and eHTNR polyol were confirmed by 1H-NMR spectroscopy. The resulting HTNR and eHTNR polyols present a unimodal size exclusion chromatography trace. The viscosity increased with epoxide fraction. The synthesized cWPU latex based on eHTNR was a stable milky-blue emulsion with well-defined size dispersion. All cWPU-eHTNR films showed good wettability, good chemical resistance, and high thermal stability, improving with the proportion of epoxide units. The mechanical properties of cWPU-eHTNR films were studied from their stress-strain curves. Moreover, the electrical properties were investigated. The cWPU-eHTNR films showed relatively low conductivity. Wettability, chemical resistance, adhesion, thermal stability, and electrical properties of cWPU-HTNR films improved with the proportion of epoxide units on the HTNR polyol. These results demonstrate a new synthesis route to develop cWPU latex based on a biosource, for coating applications.

International audience; Renewable resource based cationic waterborne polyurethanes (cWPUs) have been prepared from hydroxyl telechelic natural rubber (HTNR) with a range of number average molecular weights (Mn) (2820, 1800, and 950 g mol−1), toluene-2,4-diisocyanate (TDI), N-methyl diethanolamine (NMDEA), and ethylene glycol (EG). The chemical structure of the cWPUs was confirmed by FT-IR and 1H NMR. Particle size and zeta potential of prepared cWPUs were also characterized by ZS nanosizer. By varying the levels of Mn of HTNR, the obtained cWPUs were stable with a milky blue appearance, forming yellowish films. The smallest particle sizes of 76.4 nm were achieved using Mn of HTNR of 2820 g mol−1 while zeta potential value ranges from 67 to 71 mV were observed with increasing Mn of HTNR. Lap shear testing of these WPUs indicates their potential in real cow leather adhesive applications, with the best adhesive result coming from cWPU based on an HTNR molecular weight of 1800 g mol−1. The results show the potential of natural rubber as a green adhesive material in suitable aqueous environments.

International audience; This paper reports on the synthesis and physical properties of conducting composites based on polyaniline and polystyrene. Polyaniline composite powders are synthesized by oxidative polymerization in an acidic medium. Thermal properties are characterized by thermo gravimetric analysis and differential scanning calorimetry. UV-Visible absorption spectroscopy is also used to study the optical properties of the deposited films. The optical gap decreases from 4.6 eV to 2.7 eV with increasing polyaniline content from 0.5 to 5 wt. % confirming the improvement of the semi-conductive properties. Due to the absorption properties in near infrared of the thin composite layers they can be promising materials for optoelectronic and photovoltaic applications.

Commercial surfactants, which are inexpensive and abundant, were covalently grafted to flat and transparent electrodes, and it appears to be a simple functionalization route to design biomembrane sensors at large-scale production. Sparsely tethered bilayer lipid membranes (stBLM) were stabilized using such molecular coatings composed of diluted anchor-harpoon surfactants that grab the membrane with an alkyl chain out of a PEGylated-hydrogel layer, which acts as a soft hydration cushion. The goal of avoiding the synthesis of complex organic molecules to scale up sensors was achieved here by grafting nonionic diblock oligomers (Brij58 = C xH2 x+1(OCH2CH2) nOH with x = 16 and n = 23) and PEO short chains ((OCH2CH2) nOH with n = 9 and n = 23) from their hydroxyl (-OH) end-moiety to a monolayer of -Ar-SO2Cl groups, which are easy to form on electrodes (metals, semiconducting materials, ...) from aryl-diazonium salt reduction. A hybrid molecular coating on gold, with scarce Ar-SO2-Brij58 and PEO oligomers, was used to monitor immobilization and fusion kinetics of DOPC small unilamellar vesicles (SUV) by both quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) techniques. Using flat and transparent thin chromium film electrodes, we designed biosensors to couple surface sensitive techniques for membranes, including X-ray reflectivity (XRR), atomic force microscopy (AFM) with subnanometer resolution, and optical microscopy, such as fluorescence recovery after photobleaching measurements (FRAP), in addition to electrochemistry techniques (cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS)). The advantages of this biomembrane-sensing platform are discussed for research and applications.

International audience; A new telechelic liquid natural rubber is used to elaborate thin coating (

In order to overcome all encapsulation variations during a complex coacervation process, the replacement of gelatin cationic polymer has been performed using p(AMA). The synthesis of p(AMA) was realized through a random radical methodology. Under these conditions a polymer with 18,600 g/mol was found appropriate for optimal capsule yield and physico-chemical properties. Turbidity measurements performed during the coacervation reactions with different ratios of both CMC and p(AMA) allowed optimizing coacervation conditions. Coacervates characterizations particularly demonstrate the stability of the capsules exhibiting a break strength over 3 N/m2.

International audience; Isoconversional analysis was applied to non-isothermal bulk cure kinetics of uncatalyzed polyurethane (PU) resins based on telechelic hydoxyl natural rubber (HTNR) and poly[(phenyl isocyanate)-co-formaldehyde] (P-MDI). The dependency of apparent activation energy on conversion led to the identification of two different kinetic models, each involving two activation energies: a phenomenological model based on the Kamal–Sourour equation with non integer reaction exponents; and a new semi-mechanistic model assuming a main second order reaction between alcohols and isocyanates forming urethane linkages and a secondary reversible reaction forming allophanates that is known to become significant above 120 °C. Such a model based on mechanistic considerations allowed us to explain the variations of reactivity of the HTNR polyols with its average molecular weight.

Grafting commercial surfactants appears to be a simple way to modify electrodes and conducting interfaces, avoiding the synthesis of complex organic molecules. A new surface functionalization route is presented to build surfactant coatings with monolayer thickness grafting molecules considered as nonreactive. A monolayer of -SO2Cl functions (from a p-benzenesulfonyl chloride) was first electrografted. It showed a high reactivity toward weak nucleophiles commonly found on surfactant end-moieties such as hydroxyl groups (-OH), and it was used to covalently graft the following: (1) nonionic diblock oligomers (Brij or CiEj, CxH2x + (OCH2CH2)nOH with x = 16 and n = 23 for Brij58, x = 16 and n = 10 for Brij C10, and x = 16 and n = 2 for Brij52); (2) poly(ethylene glycol) (PEG) short chains (PEO9 for (OCH2CH2)nOH with n = 9) and mixed formula. The surface modification due to these molecular coatings was investigated in terms of wetting properties and interfacial electrochemistry characteristics (charge transfer ...

Linear and crosslinked polyhydroxyurethanes (PHUs) based on natural rubber (NR) were synthesized by a polyaddition reaction without a solvent or catalyst to exploit the reactivity of diamines or triamines with dicyclic carbonate groups. Oligo-isoprenes were obtained from the controlled oxidative degradation of NR and successive modifications of the chain ends. The syntheses of linear PHU were carried out with two approaches. The first one consisted of a reaction between amino telechelic oligo-isoprenes and aromatic or aliphatic dicyclic carbonates. The second approach proceeded through a reaction between oligo-isoprenes bearing cyclic carbonate chain ends and difunctional or trifunctional amines. The evolution of these reactions was studied by Fourier transform infrared spectrometry. The influence of the carbonate-to-amine molar ratio, the chain length of the oligo-isoprenes, and the reaction temperatures were investigated. The thermal properties of the PHUs were studied by differential scanning calorimetry and thermogravimetric analysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45427.

International audience; A controlled degradation process enabling Natural Rubber (NR) depolymerization and using the olefin metathesis reaction in ionic liquid medium is reported. Using trihexyl-(tetradecyl)phosphonium chloride (Cyphos101) and N,N-dioctylimidazolium bromide (C8C8ImBr), low-dispersity telechelic polymers are produced. With N,N-dioctylimidazolium bromide (C8C8ImBr), the degradation process could be performed for five consecutive cycles with excellent control. This degradation process was successfully applied to waste tires.

Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy is classically used to monitor homopolymerizations. In this article, this analytical technique was extended to monitor the synthesis of VIVIPRINT 300, which is a copolymer of 2-hydroxyethyl methacrylate (HEMA) and N-[3-dimethylaminopropyl]methacrylamide (DMAPMA). The calibration curves devised for this study were based on the two homopolymers P(HEMA) and P(DMAPMA). A good correlation was realized between the FTIR absorbance intensities observed respectively at 1300 cm−1 (polymerized C-O ester bond) and 1230 cm−1 (polymerized C-N amide bond) and the level of residual HEMA and DMAPMA monomers determined by GC. Application of these calibration curves to the copolymerization also exhibited a good correlation of data relating to residual monomer determination by FTIR and GC, validating the success of this spectroscopic in situ technique.

This work involved the development of a synthetic method to produce a novel bio-based triblock copolymer (PLA-NR-PLA) that consisted of poly(lactic acid) and natural rubber. The 1H NMR analysis showed the presence of new ester linkages that resulted from a reaction between the carboxyl end-groups of the PLA prepolymer and the hydroxyl end-groups of the HTNR, together with the characteristics of the PLA endblock and the HTNR midblock. The Mn of PLA-NR-PLA as determined from the GPC agreed with that from the calculation. The DSC and TGA results also substantiated the formation of a block copolymer. PLA-NR-PLA acted as a toughening agent for PLA and as a compatibilizer in the PLA/NR blend. The PLA-NR-PLA was as good as a toughening agent as NR although the PLA-NR-PLA had a much lower molecular weight than the NR. The compatibilization effect was more dominant in the blend containing 10% rubber than in the blend that contained >10% rubber. The compatibilization effect was also observed in the morphology of the blend as a reduction in the rubber particle diameter. PLA-NR-PLA not only increased the impact strength of the blends, but also increased the elongation at break.

Natural rubber is a renewable resource with a potential as precursor of a very wide range of novel polymers, including polyisoprene-based surfaces with antifouling (AF) activity. In this work, new ionic and non-ionic coatings were prepared by the photocrosslinking reaction of photosensitive cis -1,4-oligoisoprenes, bearing a variable number of ammonium groups. The photochemical crosslinking was achieved using radical (via acrylate groups) or cationic (via epoxy groups) processes. Surface properties of these coatings were studied by static contact angle measurements and AFM imaging. Assessment of bioactivity demonstrated that most of the resulting coatings showed AF potential against fouling organisms: growth inhibition of marine bacteria ( Pseudoalteromonas elyakovii , Shewanella putrefaciens , Cobetia marina , Polaribacter irgensii , Vibrio aestuarianus ) and fungi ( Halosphaeriopsis mediosetigera , Asteromyces cruciatus , Lulworthia uniseptata , Zalerion sp., Monodictys pelagica ); decreased adhesion of microalgae ( Navicula jeffreyi , Cylindrotheca closterium , Chlorarachnion globosum , Pleurochrysis roscoffensis , Exanthemachrysis gayraliae , Amphora coffeaeformis ); inhibition of attachment and/or germination of spores of Ulva intestinalis . The best AF activity was obtained with the ionic surfaces. These new coatings prepared from precursors obtained from natural rubber are in essence active by contact. As the biocidal functions are fixed covalently to the polymer chain, detectable release of biocidal products in the marine ecosystem is prevented so that a valuable environment-friendly alternative for new AF coatings is hereby proposed.

Metathetic degradation of synthetic cis-1,4-polyisoprene (PI) and styrene–butadiene copolymer (SBR) was performed with cis-1,4-diacetoxy-2-butene (DAB) as chain transfer agent (CTA) using Grubbs II catalyst. Well-defined acetoxy telechelic polyisoprene structures were obtained in a selective manner with a wide range of targeted average molecular weights from 350 g mol −1 to 98,000 g mol −1 , with a polydispersity index of around 2. Starting from SBR, a similar structure control was obtained with a range of M n from 1400 g mol −1 to 65,000 g mol −1 . It was found that precise selection of catalyst concentration and solvent is the major factor to obtain targeted products with high M n control. Moreover, preliminary tests using such a procedure have shown its efficiency starting from waste tyre. This methodology thus suggests the possibility to recycle such rubber waste leading to high value liquid rubber.

Carbon and chromium surfaces were modified by electrochemical reduction of a diazonium salt formed in situ from the sulfanilic acid. The organic layer formed was activated by phosphorus pentachloride (PCl(5)) to form a benzene sulfonil chloride (Ar-SO(2)Cl). An electrochemical study of the blocking effect and the activity of this surface was carried out on a carbon electrode. The chromium surface study was completed by X-ray photoelectron spectroscopy and atomic force microscopy to characterize the formation of a compact monolayer (0.8 nm height and roughness 0.2-0.3 nm). The compactness and the activity of this organic monolayer allowed us to affix a length dsDNA with the aim of analyzing the formation of a complex between dsDNA and a protein. The interaction of a transposase protein with its target dsDNA was investigated. The direct imaging of the nucleoproteic complex considered herein gives new insights in the comprehension of transposase-DNA interaction in agreement with biochemical data.

Bio-based polyurethane foam (PUF) was synthesized by a one-shot polymerization using hydroxyl telechelic natural rubber (HTNR) and polycaprolactone (PCL) diols as a soft segment. The effect of HTNR/PCL diol molar ratio (1/0, 1/0.5, 1/1 and 0.5/1) on the foam formation rate and physical and mechanical properties of the resulting PUF was investigated. The formation of urethane linkage and cross-linked structure were confirmed by FTIR analysis. The foams observed by scanning electron microscope revealed to have almost closed cells. The molar ratio of HTNR/PCL diol affected the foam formation rate, the average diameter of cell, the regularity of cell shape, the elongation at break and the compressive strength. The foam density slightly changed with this molar ratio whereas the specific tensile strength of all samples was in the same range. All PUFs showed relatively high compression set. The biodegradability was assessed according to a modified Sturm test. Low density polyethylene and sodium benzoate were used as a negative and positive control sample, respectively. PUF samples showed an induction time of 33 days in which the percentage of biodegradation was ~7–11 %. At the end of testing (60 days), the highest degradation (45.6 %) was found in the sample containing 1/0.5 of HTNR/PCL diol molar ratio.

This work was an initial study on the synthesis of polyurethane foams (PUF) by using diols obtained from the controlled degradation of waste tire crumbs and from polycaprolactone (PCL) followed by examination of their biodegradability. Natural rubber (NR, cis−1,4 polyisoprene) and butadiene rubber (BR) chains contained in waste tire crumbs were chemically modified into carbonyl telechelic (CTWT) and successively into hydroxyl telechelic oligomers (HTWT). Four types of PUF were prepared with different molar ratios between the HTWT and the PCL diols. CTWT and HTWT were analyzed by 1H-NMR, SEC, and FT-IR to confirm their chemical structure. Formation of the urethane bond was demonstrated by FT-IR spectra. The addition of the PCL diol increased the thermal degradation temperature of the PUF based on thermogravimetric analysis. According to scanning electron microscopy, polyhedral closed cells were obtained. The molar ratio of HTWT/PCL diols strongly affected the kinetic rate of foam formation and foam morphology. A low kinetic rate provided PUF with a high density, small cell size, and a broad cell size distribution. In order to assess biodegradation of PUF, the modified Sturm test was carried out for 60 days at ambient temperature (27–30 °C). The biodegradation of PUF containing only HTWT was 31.2% and 51.3% at 28 days and 60 days of testing, respectively whereas the PUF containing 1/0.5 HTWT/PCL diols (by mole) showed a higher biodegradation: 39.1% and 64.3% at 28 days and 60 days of testing respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44251.

International audience; Rubber is a widely available potential carbon neutral resource, both as native natural rubber state and as vulcanized state in waste tires. Herein, we describe a model synthesis of acrylate telechelic natural rubber (AcTNR) oligomers and the use of such oligomers to prepare novel acrylate resins. AcTNR oligomers are synthesized according to a two steps procedure implying a controlled C = C bond's scission of high-molecular-weight natural rubber and a further chain ends functionalization. The molar mass of the resulting AcTNR is found to be 2300 g/mol as determined by 1H NMR. AcTNR-based resins are then prepared by mixing AcTNR oligomers with various reactive diluents (RD) such as styrene, 1,4-butanediol ether, tri(propylene glycol) diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate (AcTNR:RD weight ratio 7:3). These bio-based resins are afterward cured in the presence of methyl ethyl ketone peroxide as initiator and cobalt octoate as accelerator at 80 °C and postcured at 120 °C. The cured resins offer a wide range of mechanical, thermal, and dynamic-mechanical performances. This approach could be extended to rubber tire wastes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43548.

Novel polyurethanes were successfully synthesized by a one-shot polymerization. They contained poly(e-caprolactone) diol (PCL diol) and hydroxyl telechelic natural rubber (HTNR) as the soft segment. The effect of the NCO:OH molar ratio (0.75:1.00–2.25:1.00), chain extender and PCL:HTNR molar ratio (1:1, 0.7:0.3 and 0.3:0.7) on the thermal and mechanical properties of the resulting polyurethane were investigated. FTIR analysis showed the presence of urethane linkages and crosslinking or chain branching. The derived polyurethanes demonstrated excellent mechanical properties, which depended on their chemical composition. Their tensile behavior seemed to have typical elastomeric characteristics. Polyurethanes became amorphous and showed a phase separation between the PCL diol and HTNR segments. The phase separation between the soft and the hard segments was observed by the DMTA technique whereas DSC results showed only the glass transition temperatures of the soft segment. The longer and more flexible chain and non-polarity of HTNR was responsible of a decrease in the mechanical properties and transition temperatures.

The photoinitiated polymerization of epoxidized hydroxytelechelic cis-1,4-polyisoprene and of a dual system (epoxidized/ acrylated) telechelic cis-1,4-polyisoprene in the presence of 2,2-dimethyl-1,2-hydroxyacetophenone or/and hexafluoro-phosphate triar- ylsulfonium salt has been studied by real-time infrared spectroscopy. The synthesis of photosensitives oligoisoprenes was achieved by chemical modifications of hydroxytelechelic cis-1,4-polyisoprene obtained by controlled degradation of high molecular weight cis-1,4- polyisoprene. Then, the effect of light intensity, photoinitiator concentration, addition of reactive diluent and concentration of func- tional groups on the photopolymerization process was evaluated. Concerning the cationic process, the results showed that the kinetic profile improves when photoinitiator concentration and light intensity increase. The optimum concentration of triarylsulfonium salt used as photoinitiator was determined as 5% (w/w) and the optimum light intensity was 50 mW cm � 2 . Reactive diluent (3-ethyl-3- hydroxymethyl oxetane) addition greatly improves the ultimate conversion and the polymerization rate. Subsequently, the photopoly- merization kinetic of a dual epoxidized/acrylated system was studied. The results obtained using different photoinitiator mixtures and different intensity of irradiation showed that the crosslinking of acrylate functions at the chain-end prevents the progression of the cationic process at the oxirane groups along the chain. Thus, the mobility of the cationic reactive centers was restricted by the cross- linking at the high conversion of the acrylate double bonds. V C 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 000: 000-000, 2012

Natural rubber grafted with poly(vinyl acetate) copolymer (NR-g-PVAc) was synthesized by emulsion polymerization. Three graft copolymers were prepared with different PVAc contents: 1 % (G1), 5 % (G5) and 12 % (G12). Poly(lactic acid) (PLA) was melt blended with natural rubber (NR) and/or NR-g-PVAc in a twin screw extruder. The blends contained 10–20 wt% rubber. The notched Izod impact strength and tensile properties were determined from the compression molded specimens. The effect of NR mastication on the mechanical properties of the PLA/NR/NR-g-PVAc blend was evaluated. Characterization by DMTA and DSC showed an enhancement in miscibility of the PLA/NR-g-PVAc blend. The temperature of the maximum tan δ of the PLA decreased with increasing PVAc content in the graft copolymer, i.e., from 71 °C (pure PLA) to 63 °C (the blend containing 10 % G12). The increase in miscibility brought about a reduction in the rubber particle diameter. These changes were attributed to the enhancement of toughness and ductility of PLA after blending with NR-g-PVAc. Therefore, NR-g-PVAc could be used as a toughening agent of PLA and as a compatibilizer of the PLA/NR blend. NR mastication was an efficient method for increasing the toughness and ductility of the blends which depended on the blend composition and the number of mastications.

Novel flexible polyurethane foams were successfully prepared from a renewable source, hydroxytelechelic natural rubber (HTNR) having different molecular weights (1000–3400 g mol−1) and variation of epoxide contents (EHTNR, 0–35% epoxidation) by a one-shot technique. The chemical and cell structures as well as physico-mechanical, thermal, and acoustic properties were characterized and compared with commercial polyol analogs. The obtained HTNR based foams are open cell structures with cell dimensions between 0.38 and 0.47 mm. The HTNR1000 based foam exhibits better mechanical properties but lower elongation at break than those of commercial polyol analog. However, the HTNR3400 based foam shows the best elastic properties. In a series of EHTNR based foams, the tensile and compressive strengths show a tendency to increase with increasing epoxide content and amount of 1,4-butanediol (BD). The HTNR based foams demonstrate better low temperature flexibility than that of the foam based on commercial polyol. Moreover, the HTNR based polyurethane foams was found to be an excellent absorber of acoustics. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Summary: Composite polyurethane/polyaniline (PU/PANI) films have been chemically prepared by oxidative in-situ polymerization of aniline inside the previously swelled PU film. Swelling kinetic studies have shown that for PU films the swelling degree of aniline is 25 wt.%. The dielectric and electrical properties of the composite films were measured using dielectric relaxation spectroscopy and four-probe method. Dielectric measurements as a function of temperature and frequency revealed the presence of a relaxation process for the composite PU/PANI-HCl film. This relaxation was explained in terms of interfacial polarization due to the double-layered structure of the composite film. The activation energy values found by dielectric and electrical measurements are close and this result confirms the conducting character of the PANI containing layer.

Composite polyurethane/polyaniline and polyamide-6/polyaniline films were chemically prepared by oxidative in situ polymerization of aniline inside the previously swelled matrix film. Swelling kinetic studies had shown that for polyurethane and polyamide-6 films the swelling degree of aniline was 25 wt.% and 15 wt.%, respectively. The dielectric and electrical properties of the composite films were established using dielectric relaxation spectroscopy and four-probe method. Dielectric measurements as a function of temperature and frequency revealed the presence of relaxation processes influenced by the nature of the polymer matrix, i.e. one relaxation process for the polyurethane based composite film and two relaxation processes for polyamide-6 based composite film. These relaxations were explained in terms of interfacial polarization caused by the polyaniline organisation as it was revealed by atomic force microscopy. Activation energy values obtained by dielectric and electrical measurements are close and this result confirms the conducting character of the polyaniline containing layer.

A poly(cyclopentadithiophene) matrix modified by DNA covalently fixed to the surface has been designed to study the redox and ion-exchange properties in surface-tethered DNA-conducting polymers. Voltammetric investigations show an improvement in conductivity, originating from DNA modification, probably due to changes in charged-density and size of dopant species. Cyclic voltammetry with concomitant QCM measurements indicate that the mass changes are consistent with an ejection of Na + cations associated to the anionic phosphate groups, attesting a DNA contribution to the p-doping process. So, in contrast to the classic doping patterns, the p-doping process of surface-tethered DNA-copolymer exhibits a cation-controlled transport mechanism. Impedimetric investigations indicate that for long enough DNA target sequence, nucleic acid preserves certain flexibility and is involved in the p-doping process through a diffusion-like motion. These results give new opportunities for genesensors development and for a better understanding of bioactive conducting surfaces.

New crosslinked ionic polyurethanes and copolyurethanes were yielded by reaction of telechelic cis-1,4-oligoisoprenes, bearing a variable number of ammonium and hydroxy groups, with isocyanurate of isophorone diisocyanate (I-IPDI). Aiming for a comparative study, polyurethane elastomers based on non-ionic telechelic oligomers were also synthesized. Thermo-mechanical behavior and crosslinking density of these three families of materials were investigated by DMTA and swelling test, respectively. Surface properties were examined by static contact angle measurements and AFM imaging. The bactericidal activity of the polymers was investigated by enumerating living Pseudomonas aeruginosa on material surfaces and on water suspensions. The number of attached living bacteria was found to depend on the chemical structure of the material and on the contact time between the microorganisms and the surface. An exclusive bactericidal activity was obtained with the ionic copolyurethane family. Materials with weak crosslinking density were found to release bactericidal moieties. The abilities of the polymers to prevent bacterial growth were examined through zone of inhibition experiments against P. aeruginosa, which shown a bacteriostatical effect for each synthesized material. These experiments were not sufficiently sensitive to detect the leaching of bactericidal moieties from the materials with weak crosslinking density. When the zone of inhibition experiments was performed on more sensitive bacteria, namely Staphylococcus epidermidis, the leaching of bactericidal moieties as well as bacteriostatic effect was detected. This work demonstrates the potentiality for making functional biomaterials from natural rubber, a renewable resource.

A conducting polymer sensor for direct label-free DNA detection based on a polythiophene bearing an electroactive linker group is investigated. DNA hybridization is studied by electrochemical impedance spectroscopy (EIS) and quartz crystal microbalance (QCM) techniques. Modelling of DNA hybridization by EIS measurements exhibits the contribution of nucleic acid to a superficial p-doping process. A 675-mer single-stranded DNA is produced using asymmetric PCR from a DNA sequence of a transposable element mariner and hybridized to the previously immobilized probe. Electrochemical stimulus leads to the release "on demand" of DNA fragments and the amount delivery permits to do PCR amplification.

Natural rubber (NR) is a renewable bio-based polymer, while poly(butylene succinate) (PBS) belongs to the family of biodegradable renewable polymers. In this article, novel polyurethanes (PUs) were prepared using hydroxyl telechelic natural rubber (HTNR) and hydroxyl telechelic poly(butylene succinate) (HTPBS) as soft segments, and using toluene-2,4-diisocyanate (TDI) and 1,4-butanediol (BDO) as hard segment. HTPBS oligomers of Mn¯ = 2000 and 3500 g mol−1 were synthesized by bulk polycondensation of succinic acid (SA) with BDO. The polyurethane materials were obtained by casting process after solvent evaporation. The influence of the hard segment content and the molecular weight of HTPBS on the materials’ thermo-mechanical properties were investigated by means of tensile testing, DSC, TGA, and DMTA. The obtained polyurethanes were amorphous with phase separations between hard and soft segments as well as between HTNR and HTPBS segments, and they exhibited good physical properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42943.

Natural Rubber (NR) based Polyurethanes (PU) with phosphorylated polymers as chain extenders were studied. Two types of polymers were investigated: poly-phosphonate and poly-phosphate synthesized using a RAFT methodology. Two molecular weights (5000 and 3000 g mol −1 ) were targeted with dispersity close to 1.1. The PU films were prepared from a liquid Hydroxyl Telechelic Natural Rubber (HTNR) which was obtained through a controlled degradation. The mass percentage of the chain extenders added in the PU film was varied from 1 to 8%. The films were analysed using FTIR and Raman spectroscopy. A Raman mapping in particular was used to observe the phosphorus distribution in the PU film. In the case of the poly-phosphonate chain extender, the results highlighted that only with shorter chain lengths ( n = 13), a homogeneous distribution was observed.

Fast monitoring and control quality of food products become increasingly important for public health. Among foodborne pathogenic microorganisms, bacteria are the most common foodborne pathogens in which the currently used methods are time consuming, labour-intensive and costly. This work aims to develop a new biochip potentially used for an assessment of bacterial contamination on food product. An assessment for bacterial detection employs simple FTIR spectroscopic analysis with a complimentary surface characterization by SEM technique. The biochip based on carboxylic acid functionalized polyurethane (PU) film was synthesized for bacterial detection in particular Salmonella Typhimurium. The PU in this study was synthesized from the reaction of the alcohol groups of hydroxyl telechelic natural rubber based oligomer with the isocyanate groups of 2,4-toluene diisocyanate. The carboxylic acid functional group was incorporated into the PU chain by addition of dimethylol propionic acid as a chain extender during PU preparation. The PU film having different degree of carboxylic acid was explored for the detection of S. Typhimurium. The structural and morphological changes of the PU film after loading of the bacteria were successfully detected using ATR-FTIR and SEM, respectively. The PU film developed is considered a rapid tool for S. Typhimurium detection and has a potential application for rapid food control quality.

The effects of chain extender content (ethylene diamine, EDA) and NCO/OH ratio on the properties of natural rubber-based waterborne polyurethanes (WPUs) were investigated experimentally. The particle size of WPU increased significantly with the NCO/OH ratio, in the presence of the EDA chain extender, while it was unaffected by the EDA content. The water uptake of WPU film increased with the EDA content, while the swelling in various solvents decreased. In a thermal analysis, the second decomposition stage of a WPU film increased with the EDA content and with the NCO/OH ratio that also positively affected the dynamic mechanical and mechanical properties. These factors in WPU films had no the effect on the Tg. The stress–strain curves clearly showed the change in WPU films from soft elastomeric materials to ductile and hard plastics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42505.

International audience; Transposases are specific DNA-binding proteins that promote the mobility of discrete DNA segments. We used a combination of physicochemical approaches to describe the association of MOS1 (an eukaryotic transposase) with its specific target DNA, an event corresponding to the first steps of the transposition cycle. Because the kinetic constants of the reaction are still unknown, we aimed to determine them by using quartz crystal microbalance on two sources of recombinant MOS1: one produced in insect cells and the other produced in bacteria. The prokaryotic-expressed MOS1 showed no cooperativity and displayed a Kd of about 300 nM. In contrast, the eukaryotic-expressed MOS1 generated a cooperative system, with a lower Kd (∼ 2 nm). The origins of these differences were investigated by IR spectroscopy and AFM imaging. Both support the conclusion that prokaryotic- and eukaryotic-expressed MOS1 are not similarly folded, thereby resulting in differences in the early steps of transposition.

Carbonyl telechelic cis-1,4-oligoisoprene (CTPI) obtained from high molecular weight polyisoprene through an oxidative chain cleavage reaction have been chemically modified. Thus, new well defined amino telechelic cis-1,4-oligoisoprenes have been obtained in a mass range of 1600–2300 g/mol according to two different pathways. The first approach involved a standard mesylate displacement by sodium azide followed by smooth reduction using triphenylphosphine. The second pathway implied a reductive amination sequence. Primary or secondary amine functions have thus been selectively obtained at both oligomer chain-ends depending on reaction conditions. Peculiar NMR experiments conducted on these functional oligomers confirmed a precise control of functionality during the chemical modification. Moreover, their abilities to react with toluene diisocyanate or bis(succinimidyl)carbonate have been investigated.

Degradation studies of cis-1,4-polyisoprene were carried out using first and second generation Grubbs catalysts to achieve end-functionalized acetoxy oligomers in both an organic solvent and a latex phase at room temperature. Well-defined acetoxy telechelic polyisoprene structures were obtained in a selective manner with arange of M n from 10 000 to 30 000, with a polydispersity index of around 2.5.

A conducting polymer has been obtained by anodic oxidation of 4-cyclopenta[2,1-b;3,4-b′]dithiophen-4-ylidenemethyl-N,N-diethyl-benzenesulfonamide. In this novel polycyclopentadithiophene matrix, a cathodically sensitive aryl sulfonamide group is grafted through an ethylene junction to the polymer backbone. This polymer exhibits a remarkable electroactivity in organic and aqueous solvents allowing a smooth electrochemical cleavage of the S–N bond in both media.

Novel cationic waterborne polyurethanes (cWPU) were synthesized by step-growth polymerization of hydroxyl telechelic natural rubber, molecular weight of 2800 g mol−1, toluene-2,4-diisocyanate, N-methyl diethanolamine (NMDEA) as an emulsifier. The chemical structure of cWPU was confirmed by 1H-nuclear magnetic resonance and Fourier transform infrared spectroscopy. The amounts of NMDEA and ethylene glycol under isocyanate (NCO) index of 100 on the properties of cWPU were studied. It was found that cWPU was stable under the concentration of NMDEA more than 1.50 mol and the particle sizes decreased with increasing of NMDEA content. Also, contact angle shows more hydrophilic materials by increasing of NMDEA. Extended cWPU was found in two ranges of nano size. Chain extender has strongly affected cWPU film formation, increasing of mechanical properties, and thermal properties. In addition, stress–strain curve and scanning electron microscopy image shows the change of behavior from soft elastic to ductile plastic by adding ethylene glycol. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45715.

New bio-based diblock copolymers were synthesized from poly(lactic acid) (PLA) and natural rubber (NR). NR polymer chains were modified to obtain hydroxyl telechelic natural rubber oligomers (HTNR). Condensation polymerization between PLA and HTNR was performed at 110°C during 24 or 48 h. The molecular weight of PLA and HTNR and the molar ratio PLA : HTNR were varied. The new ester linkage in the diblock copolymers was determined by 1H-NMR. The molecular weight of the diblock copolymers determined from SEC agreed with that expected from calculation. The thermal behavior and degradation temperature were determined by DSC and TGA, respectively. The diblock copolymers were used as a toughening agent of PLA and as a compatibilizer of the PLA/NR blend. PLA blended with the diblock copolymer showed higher impact strength, which was comparable to the one of a PLA/NR blend. The former blend showed smaller dispersed particles as showed by SEM images, indicating the increase in miscibility in the blend due to the PLA block. The compatibilization was effective in the blends containing ∼10 wt % of rubber. At a higher rubber content (>10 wt %), coalescence of the NR and diblock copolymer was responsible of the larger rubber diameter in the blends, which causes a decrease of the impact strength. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41426.

The accumulation of waste tires is a big environmental issue and different approaches have been proposed to eliminate or recycle this material in the end of its life. However, each approach presents drawbacks and the need for a real valorization of the tire components is still of interest. In a previous work by our group, it was demonstrated that an oxidative cleavage of the polyisoprene and polybutadiene chains contained in the tires led to the synthesis of telechelic oligomers with a ketone and an aldehyde at the chains ends. In this work, the process to obtain these carbonyl oligomers has been improved, with a particular concern for the elimination of the maximum amount of carbon black. The carbonyl oligomers can be easily reduced to hydroxyl oligomers and, in order to show the benefit of the recycling process, an application of these hydroxyl oligomers is reported: they have been used as building blocks (polyol precursors) in the preparation of polyurethane (PU) foams. The morphology of the resulting foams was observed by scanning electron microscopy technique: the images showed an almost open-cell structure and a homogeneous distribution of cell size. Mechanical (tensile and compressive strength) and thermal properties of PU foams synthesized from “recycled” oligomers from waste tires were compared to those of PU foams synthesized from analogue oligomers derived from natural rubber. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41326.

International audience; The interaction of human Rad51 protein (HsRad51) with single-stranded deoxyribonucleic acid (ssDNA) was investigated by using quartz crystal microbalance (QCM) monitoring and atomic force microscopy (AFM) visualization. Gold surfaces for QCM and AFM were modified by electrografting of the in situ generated aryldiazonium salt from the sulfanilic acid to obtain the organic layer Au–ArSO3H. The Au–ArSO3H layer was activated by using a solution of PCl5 in CH2Cl2 to give a Au–ArSO2Cl layer. The modified surface was then used to immobilize long ssDNA molecules. The results obtained showed that the presence of adenosine diphosphate promotes the protein autoassociation rather than nucleation around DNA. In addition, when the BRC4-28 peptide inhibitor was used, both QCM and AFM confirmed the inhibitory effect of BRC4-28 toward HsRad51 autoassociation. Altogether these results show the suitability of this modified surface to investigate the kinetics and structure of DNA–protein interactions and for the screening of inhibitors.

Three thiophene rings bearing n-ethoxy arylsulfonamide pendant groups were synthesized and their electropolymerization was performed at a platinum electrode. The electrochemical behaviour of the polythiophene matrix was studied both in organic and in aqueous solvent. If all polymers present a reversible n- and p-doping process in organic solvents, only one of them particularly possess a reversible p-doping in aqueous media. This phenomenon was shown to be directly related to the nature of the spacer between the thiophene ring and the aryl sulfonamide unit. Keywords: Solid phase synthesis, Aryl sulfonamide pendant unit, Modified cathode, Anodic polymerization

A novel fluorenylidene containing a ferrocene unit has been electropolymerized. In this polymer, the ferrocene unit is grafted to the main polyfluorenylidene chain as a pendant group. The polymer is electroactive in non-aqueous and aqueous media. Keywords: Anodic polymerization, Fluorenylidene, Polyfluorene, p-doping process, Post-functionalization, Ferrocenyl pendant unit

New thiophene derivatives substituted by electrochemically cleavable sulfonamide groups have been synthesised and their electrochemical behaviour has been investigated in acetonitrile. The anodic oxidation of phenyl (I)- and naphthyl (II)sulfonamide-substituted thiophenes yielded corresponding polymer films exhibiting p- and n-doping processes. The cathodic cleavage of the SN bond grafted to the polymer backbone was performed by applying a potential lower than −2.5 V (versus Ag ∣ 10−1 M Ag+) to the polymer. The efficiency of this solid-state electrochemical reaction was found to be strongly lowered when the film thickness was increased. It was demonstrated that the decrease of this parameter was less important when a copolymer electroformed from II or a phenylsulfonamide-substituted terthiophene (III) was involved. The recycling properties of this type of material were illustrated by the grafting of an aminoferrocene moiety after the cathodic cleavage step to poly(II-co-3-methylthiophene).

The synthesis of thiophenes 3-substituted by arylsulfonamide groups is described. Their electropolymerization and the characteristics of the polymers thus formed were studied, showing the importance of the nature of the spacer intercalated between the thiophene unit and the electroactive cleavable aromatic function under electron transfer. The presence of an oxygen atom in an appropriate position in the chain appears to dramatically control the electrochemical stability and the electroactivity of the polymer.

Free phosphaalkenes are prepared by stereocontrolled rearrangement of vinylphosphines and β-elimination of α,α'-dichloroalkylphosphines. Synthetic potential is evaluated in inter- and intramolecular [4+2] cycloadditions.