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  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 24 (1986), S. 1021-1037 
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Ionic interactions in blends of poly(styrene-co-styrene-sulfonic acid) and poly(ethyl acrylate-co-4-vinylpyridine) result in greatly extended rubbery regions. Measurements of dynamic shear moduli as a function of frequency at various temperatures above the glass transition indicate that time-temperature superposition is applicable in almost all cases. Relative to a blend of pure polystyrene with pure poly(ethyl acrylate), the copolymeric blends strongly resemble one another regardless of either compatibility or ion content. Higher ion content appears to enhance the extension of the rubbery plateau. True flow is not achieved even at temperatures as high as 220°C (0.1 rad/s). Flow is clearly evident in the nonionic blend at 170°C (0.1-1.0 rad/s). It is postulated that the ionic interactions are such that bond breaking and reforming are more rapid than the rate of chain slippage.
    Additional Material: 8 Ill.
    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 B: Polymer Physics 31 (1993), S. 1431-1440 
    ISSN: 0887-6266
    Keywords: polymer blend, ionomer, polystyrene copolymer, poly(2,b-dimethyl 1,4-phenylene oxide), miscibility ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Blends of poly(2,6-dimethyl 1,4-phenylene oxide) (PPhO) with the copolymer poly(styrene-co-methacrylic acid) (PS-MAA) and the ionomer poly(styrene-co-sodium methacrylate) (PS-MAA-Na), up to 10 mol% co-unit content, were investigated by dynamic mechanical thermal measurements. The PPhO/PS-MAA-Na blends are compared with PS/PS-MAA-Na blends. The blends of PPhO with PS-MAA are no longer miscible at 10 mol% acid content; this is attributed to a copolymer effect induced by the reduction of PS-PPhO interactions due to the presence of the MAA group which does not interact favorably with PPhO. The blends of PPhO with the ionomer are already immiscible at the lowest ion content studied (2.4 mol%), but become increasingly so as ion content is increased. Despite favorable PS-PPhO interactions, these blends are only a little more miscible than the PS/PS-MAA-Na blends. This is attributed to a combination of the increasing importance of the ionomer cluster phase (from which the homopolymer chains presumably are excluded) as ion content is increased, and of a copolymer effect between the homopolymers and the unclustered phase of the ionomer. These results are compared with published data indicating that blends of PPhO with another biphasic ionomer, zinc sulfonated polystyrene, are miscible. The contrasting behavior is rationalized in part by the suggestion that the copolymer effect between PPhO and the unclustered phase of the latter ionomer, but not of the former, is absent; this is related to multiplet structure and sizes. The analysis made of the above systems is extended to predict what might be the miscibility behavior between PPhO and other PS-based ionomer and related copolymer systems. © 1993 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 24 (1986), S. 1121-1135 
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dynamic melt rheology of random copolymers of polystyrene with 2-9 mol% 4-vinylpyridine was examined in their quaternized and nonquaternized forms. Time-temperature reducibility applies in all cases. Relative to the glass transition, the master curves of the nonquaternized materials are identical. Melt flow in the quaternized materials is mildly retarded, the extent increasing with ion content. At the highest ion contents, the relaxation processes appear to be of Arrhenius type. As in the glass transition region, the ionic interactions in the plateau and terminal zones are thermally labile.
    Additional Material: 10 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 24 (1986), S. 1155-1169 
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A high molecular weight styrene ionomer containing 5 mol% sodium methacrylate was blended with a styrene oligomer (MW 800) and investigated by dynamic mechanical techniques. The focus of the study is on the dynamic melt rheology of these materials, whose ratios by weight of ionomer to oligomer are 60/40, 40/60, and 25/75. The glass-transition temperature and ionic transition are first characterized by torsion pendulum measurements as a function of temperature. It appears that a maximum level of plasticization is achieved for the ionic regions, the extent depending on sample history. Time-temperature superposition is obeyed by the blend of 60 wt% ionomer, but not by the other two blends. Relaxations due to the ionic regions are clearly evident in the relaxation spectra of all three blends. Above a particular temperature, the 25 wt% blend indicates an Arrhenius type of dependence.
    Additional Material: 11 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 24 (1986), S. 1137-1153 
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The plasticizing effect of a nonpolar and a polar diluent in ionomers was studied by dynamic mechanical methods in the glassy to rubbery regions. Specifically, a carboxylate and a sulfonate polystyrene-based ionomer were investigated with variation of diethylbenzene content and of glycerol content. It was found that the nonpolar diluent plasticizes the transition by formation of ionic aggregates as well as lowering the glass transition temperature. However, the ionic regions of the carboxylate ionomer are plasticized more than those of the sulfonate ionomer. This corroborates the results of other studies which had found that the sulfonate groups in ionomers interact more strongly than the carboxylate groups. The polar diluent causes the ionic transition to disappear; this is probably due to solvation of the ions by the diluent.
    Additional Material: 12 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 48 (1997), S. 25-29 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The evidence for biphasic morphology in lightly sulfonated polystyrene (PS-SSA) ionomers neutralized by bifunctional organic cations (namely, 1,6-hexanediamine or HDA) is established by comparing their dynamic mechanical behavior, as a function of ion content and degree of neutralization, with that for metal-neutralized biphasic ionomers. The trends as a function of ion content regarding the transition temperatures and intensities of the HDA-neutralized ionomers parallel what is observed for metal-neutralized ionomers, in particular polystyrene-based ones. A small-angle X-ray scattering peak, identified as an “ionomer peak”, is observed in the PS-SSA-HDA ionomer of the highest ion content studied. Furthermore, it was observed that partial neutralization affects the cluster phase more strongly than the matrix phase. This can be explained by the contribution of the acid groups to the matrix Tg, and their ability, when present in large amounts, to affect the ionic interaction strength or facilitate ion hopping, which influences primarily the cluster Tg.
    Additional Material: 5 Ill.
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  • 7
    Publication Date: 1981-11-01
    Print ISSN: 0021-9584
    Electronic ISSN: 1938-1328
    Topics: Chemistry and Pharmacology , Education
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