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  • 1
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 2719-2734 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Polystyrenes containing up to about 20 mol % sulfonic acid are reproducibly and readily prepared by the sulfonation of polystyrene at 50°C with acetyl sulfate in 1,2-dichloroethane solution. The metal salts of sulfonated polystyrene possess extremely high melt viscosities and are soluble in single solvents such as toluene and THF only at very low sulfonate levels. Such properties are the result of the very strong ion-dipole interactions among the metal sulfonate groups. Such strong interactions can be substantially reduced through the neutralization of the sulfonic acid with ammonia and, most especially, relatively simple low molecular weight amines. Sulfonated polystyrenes varying in sulfonic acid content from about 1 mol % to about 20 mol % were neutralized with various mono-, di-, and tri-substituted alkyl amines ranging in alkyl chain length from H (ammonia) to C20, and their rheological and thermal properties were measured. As the number of substituents on the nitrogen increased, the glass transition temperature and the melt viscosity decreased. The tributylamine sulfonates possessed viscosities almost as low as unsulfonated polystyrene and the longer chain amines behaved as if internally plasticized. The properties of amine neutralized sulfonated polystyrenes are concluded to be primarily a function of amine size. Increasing the size of the amine reduces the strength of the ion-dipole interaction by preventing close approach of the amine sulfonate groups.
    Zusätzliches Material: 15 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 24 (1986), S. 581-586 
    ISSN: 0887-6258
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 443-448 
    ISSN: 0021-8383
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Broad line NMR investigations on solid L-alanine have been carried out over the temperature range 77°K to 493°K. A comparison between the observed and theoretical values of the second moment has been made, to provide check on the crystal structure and to study the molecular motions. Investigations reveal the presence of NH3 group motion at about 230°K. The activation energy for NH3 group rotation has been computed to be 7.19 ± 1.0 kcal/mole. The crystal lattice remains rigid below 230°K. There is a possibility of torsional oscillation of the CH3 group at about 352°K.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 25 (1987), S. 839-854 
    ISSN: 0887-6266
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: The preparation, rheology, and mechanical properties of a family of blends composed of transition-metal neutralized sulfonated ethylene-propylene-diene elastomers (S-EPDM) and styrene-4 vinylpyridine copolymers (SVP) are described. These polymeric materials contain relatively low levels of interacting groups (≤ 10 mol%), which are, however, sufficient for forming an intermolecular complex. A distinguishing characteristic of these blends is that the rheology and mechanical properties are strongly influenced by a coordination-type bonding between the transition metal and the basic nitrogen unit. As a result, markedly improved and enhanced physical properties are observed, especially when the stoichometric ratio of the interacting moieties are approached (SO3-/N = 1/1). This enhancement in properties is clearly exhibited in melt viscosity data, dynamic mechanical data, and thermal data. The blend morphology is also altered by complex formation, as is observed in scanning electron microscopy of the blends from which one of the ingredients was selectively extracted. At the stoichometric ratio, the blend of the olefinic elastomeric ionomer and the styrenic thermoplastic copolymer approaches a single-phase system. Such blends are otherwise completely immiscible when the coordination-type interacting groups are absent from either of the individual components. Accordingly, it was observed that nontransition-type (Na, Mg) counterions have only a marginal effect on the compatibility of these blends, as is the case in the completely unfunctionized blend components.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 28 (1990), S. 1443-1462 
    ISSN: 0887-6266
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Detailed thermal characterization of sulfo-EPDM ionomers was carried out. The endotherms observed via differential scanning calorimetry (DSC) and multiple inflections observed via thermal mechanical analysis (TMA) are speculated to be due to associated ionic species in the polymers. A large time dependence of the DSC endotherm was observed, suggesting substantial variations in the nature of the ionic species over this period. The influence of ionomer composition on thermal characteristics was probed with whole polymers and polymer fractions. In general, trends in the DSC and TMA data paralleled those expected on the basis of the anticipated effect of polymer sulfonation level, molecular weight, and counterion type on the strength of the physical crosslinking of these polymers. Both the DSC endotherms and the TMA inflection regions are rationalized in terms of a previously developed ionic-bond exchange model.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 41 (1990), S. 1479-1489 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Linear viscoelastic studies of concentrated blend solutions of metal neutralized sulfonated elastomers and low molecular weight metal stearate plasticizers are presented. The data of the magnesium and zinc salts of sulfonated EPDM polymer solutions in 100 N oil solvent as a function of magnesium and zinc stearate polar plasticizers show that addition of the latter species into the ionomeric elastomer solutions enhances their low temperature relaxation spectrum. The changes in properties are directly related to the enhancement of ionic interactions and filler effects of the plasticizers. At high temperatures, the zinc stearate molecules behave more as a conventional plasticizer. For ionomeric associating polymers, the phenomenon appears to be quite general in nature. The enhancement in properties is found to be a function of the counterion structure on the ionomer and stearate. In the case of these solution blends, the studies confirm that an ion-exchange process can occur, especially at high temperatures, resulting in the counterion on the stearate moieties “exchanging” ionic sites on the ionomer. Apparently, this process proceeds quite slowly at low temperatures. However, it is clear from these measurements that the incorporation of metal stearates into the ionomeric solution changes the network structure at both low and high temperatures.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 22 (1982), S. 499-506 
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Blends of ethylene-propylene-diene (EPDM) and of metal-neutralized, Sulfonated EPDM elastomers with polypropylene were prepared, and their structure-property relationships were investigated. Extensive rheological measurements, including linear viscoelastic dynamic mechanical studies, were conducted on the blends. As might have been expected, the properties were a strong function of the blend compositions. Both blend systems exhibited multiple transitions indicative of molecular incompatibility of the blend components. These observations are consistent with the morphologies that were observed by scanning electron microscopy using selective extraction techniques. Both blend systems revealed two continuous interwoven phases consisting of elastomer and polypropylene. However, on a relative basis, the moduli and flow of the two blend systems differed significantly; blends of sulfonated EPDM possess higher moduli and lower flow values. The physical and flow property differences between the two systems are directly attributed to the difference in the structure of the elastomer components.
    Zusätzliches Material: 17 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 449-462 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Ionomers based on propylene-acrylic acid copolymer have been prepared and their rheological behavior studied. With different cations the melt viscosity at any shear rate increases as tributylamine salt 〈 acid 〈 zinc salt 〈 sodium salt. Similarly, the activation energies for viscous flow follow the order polypropylene ∼ tributylamine salt 〈 acid ∼ zinc salt 〈 sodium salt. These results are a consequence of intermolecular interactions between salt groups for the metal acrylate derivatives and hydrogen bonding for the acid derivatives. Strong ionic interactions are absent in the tributylamine salt because of steric hindrance of the bulky amine substituents. The glass transition temperatures for these materials were equivalent. The elastic properties of these polymers follow a similar trend as does the viscosity.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
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