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  • 1
    Electronic Resource
    Electronic Resource
    D2-m-carborane-siloxanes. III. Preparation and properties of trifluoropropyl-modified polymers (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 973-981 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Linear D2-m-carborane-siloxanes with one, two, and three trifluoropropyl moieties per repeat unit were prepared by the condensation reaction between bisureidosilanes and carborane disilanol. Molecular weights between 100,000 and 220,000 were obtained. Compared to fluorosilicones, the trifluoropropyl-modified carborane-siloxanes exhibited greater thermal and oxidative stability and in certain cases comparable solvent resistance. The swelling index for carborane-siloxane elastomers decreased with increasing trifluoropropyl content, although this fluorocarbon moiety did compromise the thermal stability of the carborane system.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.170150418
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  • 2
    Electronic Resource
    Electronic Resource
    Electroinitiated polymerization of arylvinyl monomers (1979)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 1411-1418 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electroinitiated polymerizations of styrene, 2-vinylnaphthalene, and 9-vinylanthracene were compared in sulfolane and acetone solvents in the presence of ZnCl2. The relative orders of polymerization rates and polymerization efficiencies, in both solvents, were 9-vinylanthracene 〉 2-vinylnaphthalene 〉 styrene, with faster rates and higher efficiencies occurring in sulfolane. Data obtained from viscosity and gel permeation chromatography (GPC) studies indicate that the molecular weights of the polymers produced in these systems are extremely low, 〈5000. Chemical composition and infrared (IR) spectral data suggest that abnormal transfer reactions (possibly from solvent) may be occurring in the electroinitiated 9-vinylanthracene polymerizations. The polymerization mechanism appears to be cationic in these monomer-solvent systems with ZnCl2.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1979.170170515
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  • 3
    Electronic Resource
    Electronic Resource
    Photoinitiation and electroinitiation in the polymerization of 2-vinylnaphthalene (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 2673-2684 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The zinc chloride-catalyzed polymerization of 2-vinylnaphthalene (VN) with both photoinitiation and electronitiation methods was examined. Good yields were obtained with both methods, the electroinitiated process being somewhat faster. The mechanism for polymerization initiation was investigated through a detailed comparison of the kinetics. Both initiation methods show a similar response to increasing input energy and to change in salt to monomer mole ratio. Both methods indicate formation of a ZnCl2-(2-VN)2 complex as intermediate with the formation of the species being rate-determining. These results, together with other similar investigations, are then used to deduce a mechanism that involves the formation of an electronically excited donor-acceptor complex. It is argued that in certain salt-stabilized, electron-delocalized, aromatic systems, such excitation is possible in electroinitiation.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.170151112
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  • 4
    Electronic Resource
    Electronic Resource
    Electroinitiated polymerization of 2-vinylnaphthalene (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 1563-1571 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: As part of a program to extend the range of donor-acceptor-initiated polymerization processes, the electroinitiation of 2-vinylnaphthalene in a zinc chloride-sulfolane solution has been studied. Good conversion yields of well-characterized (NMR, IR, GPC, elemental analysis) poly(vinylnaphthalene) were obtained with the process showing several mechanistic similarities to other donor-acceptor salt electropolymerization systems.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.170150704
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  • 5
    Electronic Resource
    Electronic Resource
    Electrochemically initiated polymerization of styrene with tetraalkyl and -aryl group VA halide support electrolytes (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 1555-1562 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electrochemically initiated polymerization of styrene in methylene chloride solvent with the use of platinum electrodes and tetraalkyl and -aryl group VA halides (i.e., quaternary ammonium, phosphonium, and arsonium compounds) as electrolyte has been investigated. The order of reactivity of the electrolytes with respect to polymerization rate and initiation efficiency was found to be: arsonium 〉 phosphonium 〉 ammonium. Mechanisms involving the electroreduction of the group VA quaternary halides to species capable of electroinitiating polymerization are postulated. The observed losses in solution conductivities during polymerization with the quaternary phosphonium and arsonium electrolytes indicate possible interaction between the initiating radical-ionic species and the supporting electrolyte. In an attempt to further elucidate the mechanism of initiation in these systems, a separate series of experiments, employing the nonpolymerizing monomer, 1,1-diphenylethylene, has been carried out.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.170150703
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  • 6
    Electronic Resource
    Electronic Resource
    The photo- and electroinitiated polymerization of N-vinyl phthalimide (1979)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 1153-1161 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To elucidate mechanisms in electroinitiated polymerization reactions a comparison was conducted between ultraviolet (UV) photoinitiation and electroinitiation of N-vinyl phthalimide with zinc chloride as a catalyst. Both methods give low yields of a complex polymer product. A detailed analysis, infrared (IR), gel permeation chromatography (GPC), elemental, and molecular weight, conducted on the polymeric products, indicated that phthalimide ring opening was occurring and that complex mixtures of poly(N-vinyl phthalimide) derivatives were formed. Both initiation methods gave comparable results, which further indicated mechanistic similarity between photo-and electroinitiation in these donor-acceptor charge transfer polymerizations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1979.170170419
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  • 7
    Electronic Resource
    Electronic Resource
    Nuclear spin relaxation in poly(diethylsiloxane) (1975)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 13 (1975), S. 1269-1274 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Earlier work showed that heating causes poly(diethylsiloxane) to undergo a first-order transition from a semicrystalline solid to a more mobile viscous - crystalline material. The latter is composed of two phases and analogies between polymer and liquid crystal morphology and behavior have been made. The viscous - crystalline phase in PDES appears to be unique since the literature is devoid of other documented examples. In this study, spin - lattice and spin - spin relaxation times were measured over a wide temperature range. They show a glass transition at 138°K, a crystal - crystal transition at 206°K, and a transition around 250°K which results from translational motion of the polymer chains with respect to each other. This motion is observed in the amorphous phase at a lower temperature than in the crystalline phase. Translational motion in the crystalline phase is observed on melting of the crystallites. The spin - spin data permitted monitoring of the molecular motions in each phase and the data suggest that these phases exert some influence on the molecular motions of each other. The viscous - crystalline phase in PDES may represent a unique model for studying and understanding “precrystalline” behavior and structure in amorphous solids.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1975.180130701
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  • 8
    Electronic Resource
    Electronic Resource
    Some effects of melt-induced orientation on drawing of polypropylene monofilamentsIssued as NRCC #16467. (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 16 (1978), S. 599-612 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Morphological changes accompanying the deformation of polypropylene filaments with varying degrees of melt-induced orientation are examined using wide-angle x-ray scattering (WAXS), small-angle x-ray scattering (SAXS), and electron microscopy, and their behavior is compared both to completely unoriented film samples and to very highly oriented, hard elastic filaments. Melt-oriented filaments are shown to deform predominantly by a voiding mechanism at low temperatures (〈100°C), and destruction of the lamellas to produce fibrils occurs only after extensive drawing. The bimodal crystal texture of the filaments does not appear to greatly affect the low temperature deformation mechanism. High temperature (〉100°C) drawing produces a fibrillar structure containing elongated voids.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.180160403
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  • 9
    Electronic Resource
    Electronic Resource
    Driving force for hydraulic and pervaporative transport in homogeneous membranes (1975)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 13 (1975), S. 1201-1214 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Experiments were designed to demonstrate that the chemical potential gradient required for liquid transport through swollen network polymer membranes manifests itself as a concentration gradient and that the rate of transport is independent of how this gradient is established. The fluxes of various liquids through a crosslinked rubber membrane were measured in hydraulic and pervaporation modes of permeation. The pressure applied downstream in the latter act simply to fix the activity of the liquid in the downstream membrane surface. The experiments show the flux is a unique function of this activity, and it does not matter how it is established. Sorption data were used to convert these results into a plot of flux versus concentration differential across the membrane which was analyzed by Fick's law using a model for the concentration dependence of the diffusion coefficient. Measured ceiling fluxes for pervaporation for a number of liquids were found to be the same as those estimated from hydraulic permeation data. A simple mathematical representation for an ideal system is used as a pedagogical device to demonstrate the conclusions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1975.180130612
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  • 10
    Electronic Resource
    Electronic Resource
    The elongation and time dependence of the crystallinity of low-density polyethylene (1975)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 13 (1975), S. 1945-1957 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It has been presumed in studies of the orientation of low-density polyethylene and its time dependence that the degree of crystallinity remained constant with elongation and did not vary with time following elongation. This paper represents a test of this hypothesis by several methods. The change in crystallinity accompanying stretching has been followed by a modification of an x-ray method for uniaxial orientation proposed by Ruland in which diffraction peaks are resolved into crystalline and amorphous components and their respective areas are determined by two-dimensional integration over both the Bragg angle and the azimuthal angle of diffraction. The weight-fraction crystallinity is then determined from the ratio of the weighted crystalline area to the total area. There appears to be no significant variation in crystallinity up to 50% sample elongation for both slowly and rapidly stretched samples at room temperature. The dynamic crystallinity change accompanying small amplitude vibration has also been determined by the dynamic x-ray diffraction technique and found to be negligible over a wide range of frequency. The degree of crystallinity has also been evaluated from the absolute infrared absorbance of crystallinity-sensitive bands and has also been found to be independent of elongation at room temperature up to 80% elongation. Changes have also been observed by this method during relaxation at constant length following rapid extension and have also been found to be negligible. These results also indicate negligible changes in rotational isomer population. Consequently, we conclude that changes observed during relaxation and vibration arise from orientational changes rather than changes in the degree of crystallinity.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1975.180131009
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