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61.
Yohann Catel Michel Degrange Loïc Le Pluart Pierre‐Jean Madec Thi‐Nhàn Pham Luc Picton 《Journal of polymer science. Part A, Polymer chemistry》2008,46(21):7074-7090
Novel monomers 2‐(N‐methylacrylamido)ethylphosphonic acid, 6‐(N‐methylacrylamido)hexylphosphonic acid, 10‐(N‐methylacrylamido)decylphosphonic acid, and 4‐(N‐methylacrylamidomethyl)benzylphosphonic acid have been prepared in good yields for use in dental adhesives. They have been fully characterized by 1H‐NMR, 13C‐NMR, 31P ‐ NMR, and by HRMS. All monomers are hydrolytically stable in aqueous solution. Free radical homopolymerizations of these monomers have been carried out in solution of ethanol/water (2.5/1:v/v), using 2,2′‐azo(2‐methylpropionamidine) dihydrochloride (AMPAHC) as initiator. They lead to homopolymers in moderate to excellent yields. Structure of the polymers has been confirmed by SEC/MALLS and 1H‐NMR spectra. The photopolymerization behavior of the synthesized monomers with N,N′‐diethyl‐1,3‐bis(acrylamido)propane has been investigated by DSC. New self‐etch primers, based on these acrylamide monomers, have been formulated. Dentin shear bond strength measurements have shown that primers based on (N‐methylacrylamido)alkylphosphonic acids assure a strong bond between the tooth substance and a dental composite. Moreover, the monomer with the longest spacer group provides the highest shear bond strength. © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7074–7090, 2008 相似文献
62.
Synthesis of a thermally stable hybrid acene-thiophene organic semiconductor via a soluble precursor
Nicolas Y Blanchard P Roncali J Allain M Mercier N Deman AL Tardy J 《Organic letters》2005,7(16):3513-3516
An acene fused-thiophene hybrid p-semiconductor exhibiting high thermal stability has been synthesized via a soluble precursor bearing sterically interacting trimethylsilyl groups. [structure: see text] 相似文献
63.
Yohann Catel Lucie Maissiat Norbert Moszner 《Journal of polymer science. Part A, Polymer chemistry》2016,54(12):1814-1821
The novel polymerizable poly(alkenoic acid)s 1a–1c (expected = 2500, 5000, and 10,000 g/mol) were synthesized in three steps starting from tert‐butyl acrylate. A RAFT polymerization using 2,2‐(thiocarbonylbis(sulfanediyl))bis(2‐methylpropanoic acid) 4 as a chain transfer agent, followed by a Mitsunobu esterification and a deprotection of the tert‐butyl ester groups with trifluoroacetic acid, provided the desired acidic polymers in moderate to good yields. The synthesized polymers were characterized by 1H NMR spectroscopy and by gel permeation chromatography. The number‐average molecular weights measured for 1a–1c were in good agreement with the expected values. Self‐etch adhesives (SEAs) based on poly(alkenoic acid)s 1a–1c were formulated in order to investigate their adhesive properties. The addition of 1a–1c to a SEA formulation containing 10‐methacryloyloxydecyl dihydrogen phosphate resulted in a strong increase of the shear bond strength (SBS) of a dimethacrylate‐based composite to dentin. No significant influence of the polymer molecular weight on the dentin and enamel SBS was observed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1814–1821 相似文献
64.
Youssef Rizki Yohann Bréard Jean-Marie Le Breton Emeric Folcke Luc Lechevallier Wataru Kobayashi Antoine Maignan 《Solid State Sciences》2010,12(9):1661-1666
Solid state synthesis method has been used to stabilize oxygen deficient perovskite phases SrFe1?xScxO3?δ (0 ≤ x ≤ 0.5). The good homogeneity of samples is confirmed by energy dispersive spectroscopy (EDS) analysis performed with a transmission electronic microscope (TEM). By combining X-ray and electronic diffraction (ED), it is demonstrated that the cationic substitution on the B site of the perovskite induces a decrease of the oxygen content but without inducing long range ordering phenomenon. On this basis, X-ray patterns of compounds were indexed in the cubic Pm3m space group. The oxidation states of iron evidenced by Mössbauer spectroscopy, are in good agreement with the oxygen stoichiometries determined by cerimetric titration. In the SrFe1?xScxO3?δ series, the Fe3+/Fe4+ origin of the electronic conductivity is clearly evidenced. The limit compound SrFe0.5Sc0.5O2.5 is highly resistive and characterized by a cluster glass-like behaviour. Finally, negative magnetoresistivity properties are revealed for the x = 0.1 and x = 0.2 samples, reaching ?10% around the magnetic transition temperature in a 7T magnetic field. 相似文献
65.
Youssef Rizki Jean-Marie Le Breton Emeric Folcke Luc Lechevallier Yohann Bréard Antoine Maignan 《Solid State Sciences》2010,12(5):739-744
Polycrystalline samples of oxygen deficient perovskites SrFe1?xScxO3?δ (0 ≤ x ≤ 0.5) have been synthesized by direct solid state reactions. Each compound has been stabilized with two different oxygen stoichiometries. The structural study shows, firstly, the good cationic homogeneity of the samples and, secondly, that the Sc and Fe atoms are randomly distributed over the same crystallographic site, whatever the scandium content. This implies that no anionic order is possible. A detailed Mossbauer spectroscopy study clearly shows that the substitution of scandium for iron involves an oxygen content decrease which decreases the tetravalent iron content until its total disappearance for x = 0.5. The evolutions of the isomer shift, the quadrupolar splitting and the relative intensity versus the Sc3+ content are depicted in the present paper. 相似文献
66.
Mathematical Programming - We prove that every h-perfect line graph and every t-perfect claw-free graph G has the integer round-up property for the chromatic number: for every non-negative integral... 相似文献
67.
Yohann Catel Thorsten Bock Norbert Moszner 《Journal of polymer science. Part A, Polymer chemistry》2014,52(24):3550-3563
The novel polymerizable β‐ketophosphonic acids 4 , 8 , 10 , and 16 as well as the 9‐(methacryloyloxy)‐nonylphosphonic acid 20 were synthesized in four to eight steps. They were characterized by 1H NMR, 13C NMR, and 31P NMR spectroscopy and by high‐resolution mass spectra. The free‐radical polymerization of 4 , 8 , 10 , and 16 was carried out in a water/ethanol solution, using 2,2′‐azo(2‐methylpropionamidine)dihydrochloride as initiator. To evaluate the reactivity of the acidic monomers 4 , 8 , 10 , 16 , and 20 , their photopolymerization behavior was investigated by photodifferential scanning calorimeter. Copolymerizations with 2‐hydroxyethyl methacrylate, glycol dimethacrylate, and N,N′‐diethyl‐1,3‐bis‐(acrylamido)propane were studied. The homopolymerization of the corresponding β‐ketophosphonates and their copolymerization with hydroxyethyl methacrylate were also carried out. Self‐etch adhesives based on the β‐ketophosphonic acids 4 , 8 , 10 , and 16 were able to provide high shear bond strengths (SBSs) of dimethacrylate‐based composite to dentin and enamel. The β‐ketophosphonic acid 8 was also shown to exhibit significantly better adhesive properties than the corresponding phosphonic acid 20 . Indeed, the presence of the carbonyl moiety in the β‐position of the phosphonic acid group led to a strong improvement of the composite SBS to dentin and enamel. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3550–3563 相似文献
68.
Yohann Catel Vincent Besse Anaïs Zulauf David Marchat Emmanuel Pfund Thi-Nhàn Pham Didier Bernache-Assolant Michel Degrange Thierry Lequeux Pierre-Jean Madec Loïc Le Pluart 《European Polymer Journal》2012,48(2):318-330
Syntheses of novel 5-(methacryloyloxy)pentylphosphonic acid 1, 5-(methacryloyloxy)pentylidenebisphosphonic acid 2 and 1,1-difluoro-5-(methacryloyloxy)pentylphosphonic acid 3 are described. The ability of these monomers to adhere to hydroxyapatite was demonstrated using 31P CP-MAS NMR spectroscopy. Their copolymerization with N,N′-diethyl-1,3-bis(acrylamido)propane (DEBAAP) was investigated with photo differential scanning calorimetry. These mixtures exhibit a significantly higher reactivity than DEBAAP alone. Bisphosphonic acid 2 was shown to be significantly more reactive than monomers 1 and 3. Adhesive properties of these monomers were also studied. Adhesives based on bisphosphonic acid 2 and difluoromethylphosphonic acid 3 provide significantly higher dentin shear bond strength than the one based on phosphonic acid 1. 相似文献
69.
Tingting Fu Janina Oetjen Manuel Chapelle Alexandre Verdu Matthias Szesny Arnaud Chaumot Davide Degli‐Esposti Olivier Geffard Yohann Clment Arnaud Salvador Sophie Ayciriex 《Journal of mass spectrometry : JMS》2020,55(9)
The highly diverse chemical structures of lipids make their analysis directly from biological tissue sections extremely challenging. Here, we report the in situ mapping and identification of lipids in a freshwater crustacean Gammarus fossarum using matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) in combination with an additional separation dimension using ion mobility spectrometry (IMS). The high‐resolution trapped ion mobility spectrometry (TIMS) allowed efficient separation of isobaric/isomeric lipids showing distinct spatial distributions. The structures of the lipids were further characterized by MS/MS analysis. It is demonstrated that MALDI MSI with mobility separation is a powerful tool for distinguishing and localizing isobaric/isomeric lipids. 相似文献
70.