The Experts below are selected from a list of 108 Experts worldwide ranked by ideXlab platform
Virginia Cádiz - One of the best experts on this subject based on the ideXlab platform.
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Studies on thermal and flame retardant behaviour of mixtures of bis(m-aminophenyl)Methylphosphine oxide based benzoxazine and glycidylether or benzoxazine of Bisphenol A
Polymer Degradation and Stability, 2008Co-Authors: M. Spontón, Joan Carles Ronda, Marina Galià, Virginia CádizAbstract:Abstract The curing of mixtures of bis( m -aminophenyl)Methylphosphine oxide based benzoxazine and glycidylether or benzoxazine of Bisphenol A has been studied. In all samples the molar ratio of benzoxazine monomers or the benzoxazine–epoxy system was varied to achieve different phosphorus content. The phosphorus-containing polybenzoxazines have been characterized by dynamic mechanical and thermogravimetric analysis. Limiting oxygen index values indicate good flame retardant properties.
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synthesis and study of the thermal crosslinking of bis m aminophenyl Methylphosphine oxide based benzoxazine part a polymer chemistry
Journal of Polymer Science, 2008Co-Authors: M. Spontón, Marina Galià, J C Ronda, Virginia CádizAbstract:Bis(m-aminophenyl)Methylphosphine oxide based benzoxazine (Bz-BAMPO) was obtained using a three-step synthetic method from the aromatic diamine and 2-hydroxybenzaldehyde as starting materials. The structure and purity of the monomer was confirmed by elemental analysis, FTIR, ¹H NMR, ¹³C NMR and ³¹P NMR spectra. The curing kinetics of Bz-BAMPO was investigated by nonisothermal differential scanning calorimetry (DSC) at different heating rates and by FTIR spectroscopy. The isoconversional method was used to evaluate the dependence of the effective activation energy on the extent of conversion. The evolving factor analysis (EFA) method was applied to the spectroscopic FTIR data obtained in monitoring benzoxazine homopolymerizations. © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7162-7172, 2008
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synthesis and properties of thermosetting polymers from a phosphorous containing fatty acid derivative
Journal of Polymer Science Part A, 2006Co-Authors: Gerard Lligadas, Marina Galià, Juan C Ronda, Virginia CádizAbstract:A new phosphorous-containing fatty acid diepoxide was obtained from 10-undecenoyl chloride and 10-(2′,5′-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and crosslinked with 4,4′-diaminodiphenylmethane and bis(m-aminophenyl)Methylphosphine oxide. The properties of the thermosetting materials were evaluated by differential scanning calorimetry, dynamic mechanical thermal analysis, thermogravimetric analysis, and limiting oxygen index (LOI). Thermal and thermooxidative degradation was studied by gas chromatography/mass spectrometry, FTIR, 31P magic angle spinning NMR spectroscopy, and scanning electron microscopy. LOI values indicate good flame-retardant properties that are related to the formation of a protective phosphorous-rich layer that slowed down the degradation and prevented it from being total. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5630–5644, 2006
Senthilkumar Lakshmipathi - One of the best experts on this subject based on the ideXlab platform.
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impact of heterogeneous passivation of triMethylphosphine oxide and di Methylphosphine oxide surface ligands on the electronic structure of cd n se n n 6 15 quantum dots a dft study
Physica E-low-dimensional Systems & Nanostructures, 2016Co-Authors: Paramasivam Ganesan, Senthilkumar LakshmipathiAbstract:We report the significant influence of multiple capping ligands such as tri-Methylphosphine oxide (TMPO) and di-Methylphosphine oxide (DMPO) on the surface morphology and electronic structure of CdnSen (n=6, 15) quantum dots (QDs) using density functional theory (DFT). From the structural parameters the TMPO passivated structures shows strong structural distortion along non-polar 112¯0 surface. Besides, the binding energy values indicate that the TMPO ligands are weakly bound to 112¯0 surface. On introducing DMPO at 112¯0 non-polar surface from binding energy values, we observe significant surface reconstruction and stabilization of the structure due to the Se-H dative bond in addition to strong Cd–O bond. The NBO analysis indicates that charge transfer is maximum between metal and ligand in 112¯0 surface. The results of PDOS and molecular orbital (MO) analyses show that DMPO ligands significantly contribute to the occupied molecular orbitals near HOMO, which is not case in QDs with pure TMPO ligand. Further, the absorption spectra of CdSe QDs indicate that optical gaps are blue shifted by DMPOs. Hence, the multiple ligands can be employed in tuning the desired structural and optoelectronic properties of colloidal QDs (CQDs).
M S Subramanian - One of the best experts on this subject based on the ideXlab platform.
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sequential separation of lanthanides thorium and uranium using novel solid phase extraction method from high acidic nuclear wastes
Journal of Hazardous Materials, 2007Co-Authors: Ch Siva Kesava Raju, M S SubramanianAbstract:Abstract A novel grafted polymer for selective extraction and sequential separation of lanthanides, thorium and uranium from high acidic wastes has been developed by grafting Merrifield chloromethylated (MCM) resin with octyl(phenyl)-N,N-diisobutylcarbamoyl-Methylphosphine oxide (CMPO) (MCM-CMPO). The grafting process is well characterized using FT-IR spectroscopy, 31P and 13C CPMAS (cross-polarized magic angle spin) NMR spectroscopy and CHNPS elemental analysis. The influence of various physico-chemical parameters during metal ion extraction by the resin phase are studied and optimized by both static and dynamic methods. The resin shows very high sorption capacity values of 0.960 mmol g−1 for U(VI), 0.984 mmol g−1 for Th(IV), 0.488 mmol g−1 for La(III) and 0.502 mmol g−1 for Nd(III) under optimum HNO3 medium, respectively. The grafted polymer shows faster rate exchange kinetics (
M P Luda - One of the best experts on this subject based on the ideXlab platform.
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mechanistic study of thermal behaviour and combustion performance of carbon fibre epoxy resin composites fire retarded with a phosphorus based curing system
Polymer Degradation and Stability, 1996Co-Authors: S V Levchik, Giovanni Camino, L Costa, M P LudaAbstract:Abstract The fire retardant action in epoxy resins based on tetraglycidyl 4,4'-diaminodiphenylmethane (TGDDM) either alone or combined with the diglycidylether of bisphenol A (DGEBA), cured with bis(m-aminophenyl)Methylphosphine oxide (BAMPO) was studied. Comparison of oxygen index (OI) and nitrous oxide index suggests a condensed phase fire retardant mechanism. The yield of the intumescent char continuously increases providing polymer shielding upon increasing the concentration of the fire retardants. In the composite the carbon fibres play the role of inert fillers in combustion in the oxygen index test with, however, fibre orientation having an important effect. The carbon fibres suppress the intumescence behaviour of the char. The chemical mechanism of thermal degradation and charring of the resins is studied using thermogravimetry, thermal volatilisation analysis, char characterisation by FTIR, solid state NMR, X-ray, EPR and elemental analysis.
Marina Galià - One of the best experts on this subject based on the ideXlab platform.
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Studies on thermal and flame retardant behaviour of mixtures of bis(m-aminophenyl)Methylphosphine oxide based benzoxazine and glycidylether or benzoxazine of Bisphenol A
Polymer Degradation and Stability, 2008Co-Authors: M. Spontón, Joan Carles Ronda, Marina Galià, Virginia CádizAbstract:Abstract The curing of mixtures of bis( m -aminophenyl)Methylphosphine oxide based benzoxazine and glycidylether or benzoxazine of Bisphenol A has been studied. In all samples the molar ratio of benzoxazine monomers or the benzoxazine–epoxy system was varied to achieve different phosphorus content. The phosphorus-containing polybenzoxazines have been characterized by dynamic mechanical and thermogravimetric analysis. Limiting oxygen index values indicate good flame retardant properties.
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synthesis and study of the thermal crosslinking of bis m aminophenyl Methylphosphine oxide based benzoxazine
Journal of Polymer Science Part A, 2008Co-Authors: M. Spontón, Marina Galià, M S Larrechi, J C Ronda, V CadizAbstract:Bis(m-aminophenyl)Methylphosphine oxide based benzoxazine (Bz-BAMPO) was obtained using a three-step synthetic method from the aromatic diamine and 2-hydroxybenzaldehyde as starting materials. The structure and purity of the monomer was confirmed by elemental analysis, FTIR, 1H NMR, 13C NMR and 31P NMR spectra. The curing kinetics of Bz-BAMPO was investigated by nonisothermal differential scanning calorimetry (DSC) at different heating rates and by FTIR spectroscopy. The isoconversional method was used to evaluate the dependence of the effective activation energy on the extent of conversion. The evolving factor analysis (EFA) method was applied to the spectroscopic FTIR data obtained in monitoring benzoxazine homopolymerizations. © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7162–7172, 2008
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synthesis and study of the thermal crosslinking of bis m aminophenyl Methylphosphine oxide based benzoxazine part a polymer chemistry
Journal of Polymer Science, 2008Co-Authors: M. Spontón, Marina Galià, J C Ronda, Virginia CádizAbstract:Bis(m-aminophenyl)Methylphosphine oxide based benzoxazine (Bz-BAMPO) was obtained using a three-step synthetic method from the aromatic diamine and 2-hydroxybenzaldehyde as starting materials. The structure and purity of the monomer was confirmed by elemental analysis, FTIR, ¹H NMR, ¹³C NMR and ³¹P NMR spectra. The curing kinetics of Bz-BAMPO was investigated by nonisothermal differential scanning calorimetry (DSC) at different heating rates and by FTIR spectroscopy. The isoconversional method was used to evaluate the dependence of the effective activation energy on the extent of conversion. The evolving factor analysis (EFA) method was applied to the spectroscopic FTIR data obtained in monitoring benzoxazine homopolymerizations. © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7162-7172, 2008
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synthesis and properties of thermosetting polymers from a phosphorous containing fatty acid derivative
Journal of Polymer Science Part A, 2006Co-Authors: Gerard Lligadas, Marina Galià, Juan C Ronda, Virginia CádizAbstract:A new phosphorous-containing fatty acid diepoxide was obtained from 10-undecenoyl chloride and 10-(2′,5′-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and crosslinked with 4,4′-diaminodiphenylmethane and bis(m-aminophenyl)Methylphosphine oxide. The properties of the thermosetting materials were evaluated by differential scanning calorimetry, dynamic mechanical thermal analysis, thermogravimetric analysis, and limiting oxygen index (LOI). Thermal and thermooxidative degradation was studied by gas chromatography/mass spectrometry, FTIR, 31P magic angle spinning NMR spectroscopy, and scanning electron microscopy. LOI values indicate good flame-retardant properties that are related to the formation of a protective phosphorous-rich layer that slowed down the degradation and prevented it from being total. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5630–5644, 2006