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  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 1365-1365 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 3163-3172 
    ISSN: 0887-624X
    Keywords: miscilibilty window ; polymer blends ; hydrogen bonding ; poly(styrene-co-4-vinylphenylmethylphenylsilanol) ; FT-IR ; glass transition temperature ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymer blends consisting of poly(styrene-co-4-vinylphenylmethylphenylsilanol) (ST-VPMPS) and poly(n-butyl methacrylate) (PBMA) have been investigated. The experimental results showed that miscible blends were formed when ST-VPMPS copolymers contained 9-56 mol % silanol functional groups. Comparison of the results with poly(styrene-co-4-vinylphenyldimethylsilanol) (ST-VPDMS)/PBMA blends revealed that the miscibility window was shifted to a higher silanol composition in the present system in which a stronger hetero-associated hydrogen bonding interaction was present. The results were discussed in terms of steric shielding and electron-withdrawing effects of the phenyl substituent bound directly to the silicon atom. © 1996 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1425-1429 
    ISSN: 0887-624X
    Keywords: anomalous viscosity ; rodlike polyelectrolytes ; sulfonated poly(2-benzoyl-1,4-phenylene) ; aqueous solution ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two stereoisomeric poly(2-benzoyl-1,4-phenylene)s were synthesized. Polymer I has exclusively a head-to-tail structure; however, polymer II contains both head-to-head and head-to-tail units. The sulfonation reaction of polymers I and II was found to occur mainly on the meta position of the benzoyl group on the phenylene backbone. The viscosities of polymers Ia (27% sulfonated) and Ic (51% sulfonated) in aqueous solutions at 25°C were measured with and without NaBr addition. Upon the addition of NaBr (0.05 and 0.1M), the reduced viscosities were found to increase gradually and reach a constant value in each case after standing at room temperature for 30-40 h. Without NaBr, the time effect was not found. The reduced viscosities of solutions with NaBr were also higher than those without the salt. These results are quite different from the typical “polyelectrolyte” behavior. A possible explanation of the salt effect of rigid rodlike polymers such as sulfonated poly(2-benzoyl-1,4-phenylene) is discussed. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1425-1429, 1998
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 199 (1998), S. 1003-1011 
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A series of hydroxypropyl cellulose (HPC) derivatives with, on the average, 3, 2, 3/2, 1, 1/2, 1/3 alkyl side chains (18 carbons) on each anhydroglucose unit were synthesized. X-ray studies indicate that layered structures prevail in most of these HPC derivatives, even in the sample containing only one alkyl side chain per two rings, i.e. C18(1/6)HPC. The polymers were able to pack in better ordered arrays in the solvent-cast films than in as-made samples obtained by precipitation from a nonsolvent. Side chain melting endotherms were observed for C18(3/3), C18(2/3), C18(1/6), and C18(1/9)HPC's. In C18(1/2) and C18(1/3)HPC's, side chain melting enthalpies were negligible but isotropization enthalpies were unexpectedly large. The isotropization temperatures and the associated enthalpies remained almost constant in differential scanning calorimetry (DSC) heating/cooling cycles. Distinct morphological features were observed under the cross polarized optical microscope (POM) after shearing the samples in the molten state. The degree of side chain substitution has a profound influence on the polymer morphology.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 33 (1995), S. 71-75 
    ISSN: 0887-6266
    Keywords: rigid polymer ; sulfonated poly(p-phenylene terephthalamide) ; polymer aggregation ; solution viscosity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The viscosities of dilute solutions of poly(p-phenylene terephthalamide), PPTS, in dimethylacetamide, water, and their mixtures were determined. The reduced viscosity plot in dimethylacetamide shows a negative slope. When the water content in the mixed solvent in 90% or higher, there is an upswing in the reduced viscosity values at concentrations below 0.1 g/dL. The latter behavior suggests a “polyelectrolyte” effect. However, an association model was found to be able to explain the viscosity behaviors in both solvents. ©1995 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 33 (1995), S. 537-545 
    ISSN: 0887-6266
    Keywords: miscibility ; P3OT/EVA blends ; solvatochromatic shift ; solid state ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mixing of electrically conducting polymers in the undoped state with flexible polymers has been limited due to the stiffness of the delocalized coplanar backbone. The substitution with alkyl side chains has resulted in the distortion of the aromatic rings in the backbone with an increase of the flexibility. The alkyl substituents also prevent the thiophene back-bones from packing together, thus making blending with other polymers promising. We have investigated the phase behavior of poly(3-octylthiophene) (P3OT) with a flexible polymer, poly(ethylene-co-vinylacetate) (vinylacetate composition 20%, EVA20), and defined a miscibility window based on melting point data, on cloud point measurements, and on analysis by optical microscopy. The miscible region has been studied by UV-VIS and CPMAS NMR spectroscopies. A UV absorption in the visible region originates from a π-π * transition in the delocalized structure of P3OT, and a change in the length of the conjugated segment in the backbone results in a shift of this absorption. A gradual solvatochromatic shift of P3OT in the solid state with dilution was observed in the miscible region. T1 relaxation times for the methylene carbons in solid state show a gradual change in the relaxation process as a function of composition. © 1995 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 7 (1996), S. 553-559 
    ISSN: 1042-7147
    Keywords: polymer blends ; interpolymer complexes ; hydrogen bonds ; glass transition temperature ; poly(styrene-co-4-vinylphenylmethylphenylsilanol) ; poly(N-vinylpyrrolidone) ; 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
    Notes: Polymer blends of poly(N-vinylpyrrolidone) (PVPr) and poly(styrene-co-4-vinylphenylmethylphenylsilanol) (ST-VPMPS) copolymers with varying amounts of VPMPS monomer units have been investigated. Glass transition temperature (Tg) measurements indicated that miscible blends of PVPr with ST-VPMPS copolymers were formed when the copolymers contained 9 mole% VPMPS or more. In addition, precipitated interpolymer complexes were formed from solution blending when the copolymer contained 31 mole% VPMPS or more. Enhanced Tgs were found for most miscible blends. Fourier transform infrared spectroscopy studies revealed that the hetero-associated hydrogen bond between the silanol and amide carbonyl groups was stronger than that of the silanol self-associated hydrogen bonds of the copolymers. Tg comparisons of the ST-VPMPS/PVPr miscible blends with the previously reported poly(styrene-co-4-vinylphenyldimethylsilanol) and PVPr (ST-VPMPS/PVPr) miscible blends were made. The enhanced Tgs of the miscible ST-VPMPS/PVPr blends were attributed to a close-packed hetero interpolymer chain segments associated with the “free volume” changes due to the formation of strong hetero-associated hydrogen bond.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 6 (1995), S. 413-417 
    ISSN: 1042-7147
    Keywords: triblock copolymer ; PEO ; PDMS ; 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
    Notes: A triblock copolymer of the ABA type in which both components were crystallizable was synthesized. The A block was poly(ethylene oxide), PEO, and the B block, poly(dimethyl siloxane), PDMS. Upon cooling from the melt to liquid nitrogen temperature, the PEO block crystallized at around 40°C. When the copolymer was heated from -170°C after quenching, glass transition, crystallization and melting of the PDMS middle block were identified in the thermogram at -117°C, -74°C and -42°C, respectively. The degree of crystallinity of the PDMS block was estimated from the heat of fusion to be about 27%. The growth rates of the PEO spherulites were reduced by the presence of the middle block.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 62 (1996), S. 1427-1436 
    ISSN: 0021-8995
    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
    Notes: The transport properties of He, H2, CO2, O2, N2, and CH4 gases in solvent cast, HCl doped, and undoped polyaniline (PANi) membranes were determined. Measurements were carried out at 40 psi pressure from 19°C to 60°C. An excellent correlation was found between the diffusion coefficients and the molecular diameters of gases. The solubility coefficients of gases were found to correlate with their boiling points or critical temperatures. The sepa-ration factors for CO2/N2 and CO2/CH4 are dominated by the high solubility of CO2. These correlations enable us to predict the permeability, diffusion, and solubility coefficients of other gases. After the doping-undoping process, the fluxes of gases with kinetic diameters smaller than 3.5 Å increased but those of larger gases decreased. This results in a higher separation factor for a gas pair involving a small gas molecule and a larger one. © 1996 John Wiley & Sons, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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