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The reactions between benzylbromide or α,α′-dibromo-meta-xylene (DBMX) and sodium 1,2,3,4,5-pentamethylcycopenta-1,3-dienide (CpMe5⊝, Na⊕) give only the expected pentamathylcyclopentadiene derivatives with a good yields. These products lead to endo isomer adducts via a Diels–Alder reaction with maleimide.New low molecular weight polypentamethylnadimides were obtained in this way from the Diels–Alder...
The purpose of this paper is to evaluate the respective hydrolysis stability of phthalic and naphthalenic imide structures through the study of model compounds. The NMR and IR spectroscopic analyses of model compounds, before and after aging in water, at temperature representative of fuel cell working temperature, indicated structural modifications according to imide ring structure. The phthalic model...
Series of sequenced sulfonated naphthalenic polyimides with improved solubility were prepared by polycondensation in m-cresol using aromatic diamines containing phenylether bonds and/or bulky groups. Sulfonated polyimides were characterized by NMR and IR spectroscopies. Membranes were prepared by solution casting method and characterized by determining the ion-exchange capacity, water swelling, proton...
The reaction of α,α′-dibromometaxylene (DBMX) with sodium cyclopentadienide (CpNa) gives several oligomers, which were characterized by Size Exclusion Chromatography (SEC) and Liquid Secondary Ion Mass Spectroscopy (LSIMS). The obtained oligomers came from two competitive mechanisms after an anionic substitution of the DBMX by CpNa. The first was based on the proton transfer between the monosubstituted...
Reaction between benzylbromide and sodium cyclopentadienide leads to a mixture of dienes. These can be identified by several techniques such as size exclusion chromatography, mass spectroscopy (MS) and high performance liquid chromatography/MS coupling. Their structure is confirmed by analysis of adducts obtained after reaction of N-(4-benzoyl)-phenylmaleimide with these dienes.
A new transamidation reaction, between an aliphatic secondary amide and an aromatic nitrile, leading to an aromatic amide and an aliphatic nitrile is described in this article. The best conditions have been established: 300°C, no solvent, 2h, 1wt.% PPA as catalyst. Yields were found to be independent of the nature of para substituents, but strongly decrease for an ortho substituted compound. NMR studies...
The thermal polymerization of arylacetylene compounds has been studied from a monofunctional model compound, 4-(hexyloxy)phenylacetylene I. I was synthesized and bulk polymerized under several experimental conditions. The reaction products were analysed by chromatography, spectroscopy and spectrometry techniques. The observed average polymerization degree is low. The lowest molecular weight compounds...
Four linear dimers of 4-(hexyloxy)phenylacetylene I have been synthesized and thermally polymerized under the same conditions which were used for I. The polymerization of monomer and linear dimer mixtures as also studied. The reaction products were analysed by chromatography, spectroscopy and spectrometry techniques. The experimental results led us to conclude that the linear dimers are not reaction...
The present paper deals with the synthesis and the characterization of negative-type soluble photosensitive polyimides based on benzhydroltetracarboxylic dianhydride. These polymers were prepared either by a thermal or chemical imidization, and the photoreactive methacryloyl group was introduced through the reaction between the hydroxyl group and the isocyanate group of methacryloyl isocyanate to...
New side-chain soluble polyimides bearing Disperse Red One (DR1) groups have been synthesized and characterized. Thin films prepared by spin coating and poled with the corona technique at 200°C have nonlinear optical (NLO) coefficients d33 near 60 pm/V, determined by second-harmonic generation (SHG) at 1064 nm. The thermal stability of the SHG signal for the side-chain polymer has been compared with...
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