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  • 1
    Electronic Resource
    Electronic Resource
    Enhanced efficiency of polymer light emitting diodes utilizing oxadiazole polymers (1995)
    Weinheim : Wiley-Blackwell
    Advanced Materials 7 (1995), S. 839-842 
    Details
    ISSN: 0935-9648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/adma.19950071004
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  • 2
    Electronic Resource
    Electronic Resource
    MATERIAUX TRIPHASIQUES ALVEOLAIRES POLYMERE / CHARGE / LIQUIDE OU GAZ. Préparation de Matériaux triphasiques Polystyrène / billes de Verre / Eau ou AirDédié au Prof. Dr. D. Braun à l'occasion de son 60ème anniversaire (1991)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 185 (1991), S. 227-237 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: New three phases composite materials made of glassbeads as filler, water as liquid dispersed phase and polystyrene as matrix were obtained by polymerization of a water in oil emulsion formed by water dispersed in styrene in which glass beads are added. For this purpose glass beads have to be modified by silanization by a coupling agent 3-(Trimethoxysilyl)propylmethacrylate (TPM) or a silane Octadecyltrichlorosilane (ODMS), in order to prevent the wetting of the glass by water. Only low coverage of the glass surface by the coupling agent (0,05% of TPM) are convenient for the preparation cellular materials having good mechanical properties. At higher coverage ratio, strong hydrophobic glass beads are obtained which destabilize the water / styrene emulsion and lead to macroporous products. Study of the rheology of the filled emulsion appears to be the more simple and more sensitive method to determine the level of wettability of the glass bead by the emulsion which is the most significant parameter for the preparation of such three phases composite materials. Composite materials made of glass beads, air and polystyrene are simply obtained by evaporation of water under vacuum.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1991.051850121
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  • 3
    Electronic Resource
    Electronic Resource
    Séparation d'un copolymère greffé de l'homopolymère correspondant par la méthode des gels réversibles, 1. Introduction et principe de la méthode  -  formation de gels réversibles (1973)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 174 (1973), S. 105-115 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: A new technique, based on the formation of reversible gels is proposed for the separation of grafted copolymer from the homopolymer corresponding to the grafts. The method is developed particularly with respect to its application to ABS resins.It is shown that, if the main chain carrying the grafts (polybutadiene) is supplied with COOH groups, reversible cross-linking can be obtained by dipolar association of neutralized COOH groups (e.g. by CH3ONa). When dissolved in a mixture of an apolar solvent and a solvent (CH3OH) solvating the COONa associates, such a polymer forms a gel, if the solvating agent is eliminated. This cross-linking by association of COONa dipols leads to a nearly total insolubility of the carboxylated polymer.Renewed addition of the solvating agent leads to a dissolution of the gel phase. The mixture benzene/CH3OH has been chosen for effectuating the cycles gelation-dissolution; methanol being easily eliminated by azeotropic distillation at ordinary temperature.Optimal conditions for the reversible gel formation have been given.This sol-gel separation technique can be applied for the purification of graft copolymers.
    Notes: Une nouvelle technique, basée sur la formation de gels réversibles, est proposée pour la séparation d'un copolymère greffé de l'homopolymère correspondant aux greffons. La mise au point de la méthode a été faite en vue de son application aux résines ABS.On montre ainsi que si le tronc porteur des greffons (polybutadiène) a été muni de groupes COOH, une réticulation réversible peut être obtenue par association dipolaire des groupes COOH salifiés (p. ex. par CH3ONa). A partir d'un tel polymère, en solution dans un mélange de solvant apolaire et d'un solvatant (CH3OH) des associats COONa, on provoque la gélification par élimination du solvatant. Cette réticulation par association entre dipoles COONa permet l'insolubilisation presque totale du polymère carboxylé.Une nouvelle addition de solvatant provoque la dissolution de la phase gel.Le mélange benzène/CH3OH a été choisi pour effectuer les cycles gélification-dégélification, le méthanol pouvant être éliminé aisément par distillation azéotropique à température ordinaire.Les conditions optimales de formation du gel réversible ont pu être définies.Cette technique de séparation sol-gel peut être transposée aux copolymères greffés, en vue de leur purification.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1973.021740111
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  • 4
    Electronic Resource
    Electronic Resource
    Influence de la solvatation préférentielle dans les réactions de greffage. Polydispersité en composition des copolymères SAN dans les résines ABS (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 3523-3529 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: ABS resins formed by copolymerization of styrene (S) and acrylonitrile (AN) in the presence of polybutadiene, consist of a mixture of SAN graft copolymer on polybutadiene and of ungrafted SAN copolymer. After separation and analysis, the AN contents of the grafted and ungrafted SAN are compared. The change of the AN contents as a function of the conversion and the concentration of polybutadiene is studied.As a consequence of the preferential solvation of polybutadiene by styrene and the initiator, the grafted SAN has a lower AN content than the non grafted SAN.At low conversions, where preferential solvation is maximum, it is also possible to show the presence of non grafted SAN which is formed in the polybutadiene coil or polybutadiene medium (“internal free SAN”). The characteristics of this “internal free SAN” are similar to those of the grafted SAN and especially its AN content is lower than that of SAN copolymer prepared under azeotropic conditions in the absence of polybutadiene.
    Notes: Par copolymérisation du styrène (S) et de l'acrylonitrile (AN) en présence de polybutadiène, conduisant aux résines ABS, il se forme du copolymère greffé et du SAN libre. Après séparation et analyse du copolymère greffé, on compare la teneur en AN du SAN greffé et du SAN libre.On étudie l'évolution de ces teneurs en fonction du taux de conversion et pour différentes concentrations en polybutadiène.En raison de la solvatation préférentielle du polybutadiène par le styrène et le promoteur, le SAN greffé a une teneur en AN inférieure à celle du SAN libre.Aux faibles taux de conversion, lorsque la solvatation préférentielle est maximum, on peut également mettre en évidence du «SAN libre interne», se formant dans le milieu polybutadiène, et dont les caractéristiques sont similaires à celles du SAN greffé. Ce «SAN libre interne» présente notamment un taux en AN plus faible que les copolymères SAN préparés dans des conditions azéotropes en absence de polybutadiène.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021751217
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  • 5
    Electronic Resource
    Electronic Resource
    Effet émulsifiant des copolymères séquencés. Nouveau type de morphologie des alliages de polymères polystyrène-polyisoprène (1978)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 179 (1978), S. 2569-2572 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1978.021791024
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  • 6
    Electronic Resource
    Electronic Resource
    Interpolymer complex between poly(ethylene oxide) and poly(acrylic acid): Viscometric studies in THF-water mixturesDedicated to Prof. W. Kern on his 75th birthday (1982)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 183 (1982), S. 481-487 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Systematic studies were performed on interpolymer complex formation between Poly(acrylic acid) (PAA) and poly(ethylene oxide) (PEO) in THF-water mixtures of different compositions. Viscosity behaviour during complex formation in mixed solvents was found to be entirely different from that observed by other workers in aqueous and in pure organic solvents. The result are interpreted in terms of, (a) preferential solvation of the polymer, (b) Probable change in conformation of the polyelectrolyte moleculer. (c) association of complex molecules in a medium of low dielectric constant, and (d) expected disordering of bound water molecules around PEO by THF. Irrespective of solvent composition, interpolymer complex of PAA and PEO was always found to have 1:1 unit mole ratio.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1982.021830217
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  • 7
    Electronic Resource
    Electronic Resource
    Étude de la polymérisation du styrène en émulsion inverse (1975)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 176 (1975), S. 1393-1409 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The polymerization of reversed emulsions water in styrene prepared with polystyrene-polyethyleneoxide block copolymers (Cop PS-POE) has been studied. The kinetics of this polymerization has been studied as a function of the parameters: type and concentration of initiator, phase ratio water/styrene, concentration of Cop PS-POE, molecular characteristics of Cop PS-POE.The type of the emulsion can be regulated by the characteristics of the Cop PS-POE and by the phase ratio water/styrene. The initiation of the polymerizations can be achieved by water soluble initiators (K2S2O8). Correlations could be established between the rate of polymerization and the initiator concentration, the amount of water in the reversed emulsions and the concentration of Cop PS-POE. It was shown furthermore that the rate of polymerization increases with the POE content of two-block copolymers and that three-block copolymers are more appropriate for the polymerization in reversed emulsions. Finally the main influence of the water/styrene interface was demonstrated which regulates the transfer of radicals from the aqueous into the organic phase.
    Notes: On a étudié la polymérisation d'émulsions inverses eau dans styrène préparées à l'aide de copolymères séquencés polystyrène-polyoxyéthylène (Cop PS-POE). L'étude cinétique a été effectuée en fonction des paramètres: nature et concentration en initiateur, rapport des phases eau/styrène, concentration en Cop PS-POE, caractéristiques moléculaires des Cop PS-POE.Le type d'émulsion peut ětre réglé par les caractéristiques du Cop PS-POE et par le rapport eau/styrène. L'amorçage des polymérisations peut ětre effectué par des initiateurs solubles dans l'eau (K2S2O8). Des corrélations ont pu ětre établies entre la vitesse de polymérisation et la concentration en initiateur, la proportion d'eau dans les émulsions inverses et la concentration en Cop PS-POE. On a montré par ailleurs que la vitesse de polymérisation augmente avec la teneur en POE des copolymères biséquencés et que les copolymères triséquencés sont plus favorables pour la polymérisation en émulsion inverse. On a enfin démontré l'influence de l'interface eau/styrène qui conditionne le transfert de radicaux de la phase aqueuse à la phase organique.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1975.021760514
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  • 8
    Electronic Resource
    Electronic Resource
    Synthèse de polymères ω-hydroperoxyde (1977)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 178 (1977), S. 1249-1258 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The general conditions are described for the synthesis of ω-hydroperoxy polymers by reaction of oxygen with C—Li bonds of anionic living polymers. Secondary reactions as interchain coupling and the formation of alcohols are also discussed. In order to obtain a quantitative hydroperoxydation the following experimental parameters must be observed: (a) slow addition of the living solution to a polar solvent saturated by oxygen; (b) low concentration of living ends; (c) bulky terminal units; (d) lowest possible temperature.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1977.021780503
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  • 9
    Electronic Resource
    Electronic Resource
    Dimethylsiloxane-ethylene oxide block copolymers, 1. Microphase separation of low segment mass copolymers and their compatibility with water and oil (1984)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 2625-2645 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Ternary phase diagrams of linear tri-block and multi-block copolymers consisting of poly(dimethylsiloxane) with a constant segment mass of M̄n = 103 and varying poly(oxyethylene) segment masses in the range 100 ≤ M̄n ≤ 2000 with water and oil (cyclohexane) are reported. Also binary mixtures of the same copolymers with water and oil are investigated by differential scanning calorimetry (DSC). Microphase separation of the copolymers and different states of water are detected as a function of composition and structure of the copolymers as well as oil and water content, respectively. The results are discussed in terms of a model having an interphasial zone where intermixing of the dissimilar segments occurs.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1984.021851214
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  • 10
    Electronic Resource
    Electronic Resource
    Etude des proprietes surfactives des copolymeres sequences (1985)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 13 (1985), S. 157-170 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The surfactive properties of block copolymers are reviewed on the bases of studies which we have carried out during the last decade.The solution properties of block copolymers have been studied extensively in terms of their colloid-chemical behavior in selective solvents and their interfacial activity in two-phase systems. Micelle formation has been examined for hydrophilic-hydrophobic block copolymers. The micellar characteristics such as aggregation number have been correlated to the molecular characteristics, e.g. structure, molecular weight, composition, of di- and triblock copolymers based on polystyrene and poly(ethylene oxide).The emulsifying effect of block copolymers and the preparation of oil-water and oil-oil emulsions has been reviewed.In addition the surfactive properties of block copolymers are illustrated in the case of “polymeric oil-oil” and “polymeric water-water” emulsions which are formed by two incompatible polymers in the presence of a common solvent ; an organic solvent or water, respectively.The important factors, e.g. interfacial tension, interfacial thickness, molecular characteristics of the polymers, affecting the interfacial activity of the block copolymers and thus the stability of the “polymeric emulsions” are investigated.By a theoretical approach, and in particular by considering the interfacial characteristics of a liquid-liquid two-phase system, it was possible to define the optimum conditions leading to stable oil-water, oil-oil and to “polymeric emulsions”.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1985.020131985112
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