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  • Polymer and Materials Science  (7)
  • 1
    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: An interesting series of high molecular weight thermoplastic polymers, based on dihydric phenols and epichlorohydrin, have been prepared. The polymers have, in common, a structure which can be represented by the general repeating unit where E is a radical residuum from a dihydric phenol. Certain properties appear characteristic of this class of polymers. All contain some chain branching through the secondary hydroxyl group. They are amorphous, noncrystallizable, transparent, tough, and thermally stable. They show two glassy state transitions, a minor transition at about -70°C. and a major transition at a considerably higher temperature. This family of polymers provides an excellent means for studying structure-property correlations. Data are reported showing the effect of the structure of the dihydric phenol moiety (E) on the major glass transition temperature and on certain barrier properties of a series of these polymers. The polymer prepared from 2,2-bis(4-hydroxyphenyl) propane, bisphenol A, is considered typical of this series; its mechanical and physical properties are described in somewhat more detail and compared with properties of certain commercial polymers.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 2
    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 glass transition temperature and gas barrier properties of a number of high molecular weight thermoplastic hydroxyether copolymers have been determined. These copolymers were derived from mixtures of two dihydric phenols and epichlorohydrin. The property data are analyzed in terms of copolymer composition and the random or alternating distribution of monomer units in the polymer chains. In general, the glass transition temperatures of the copolymers were found to be intermediate between the values for the two homopolymers. In one system, good agreement between the experimental data and a simplified equation for the prediction of glass transition temperatures of amorphous, random copolymers was obtained. No differences in the glass transition behavior of random and alternating hydroxyether copolymers could be detected. Gas barrier properties, in general, were found to be intermediate in value between those of corresponding homopolymers. The exceptions are discussed in terms of polymer structure variations.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 7 (1963), S. 2153-2160 
    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 esterification of high molecular weight hydroxyether polymers, derived from dihydric phenols and epichlorohydrin, has been studied. The esters of an assortment of monobasic acids, both organic and inorganic, were prepared by reaction of acid halides, anhydrides, esters or free acids with the secondary hydroxyl group in the polymer repeating unit. The effects of the structure of the acid radical and the degree of esterification on polymer properties were determined. In general, esterification resulted in a lowering of the major glass transition temperature of the polymer. This was true at all levels of esterification. Decreased chain symmetry and decreased hydrogen bonding appeared to be the major causes of the observed effect. Permeability of the polymers to oxygen and water vapor was increased by esterification. The increases was found to correlate well with the size and polarity of the acid radical. Some additional properties of the ester derivatives were examined in less detail.
    Additional Material: 1 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 8 (1964), S. 541-541 
    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
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 3 (1965), S. 3843-3851 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The gas permeation behavior of three isomeric polyhydroxyethers has been studied with the use of hydrogen, helium, oxygen, and carbon dioxide as the test gases. Amorphous polymers were prepared from epichlorohydrin and 1,8-, 2,8-, and 1,2-bis(4-hydroxyphenyl)menthane at equivalent molecular weight levels and therefore differed only in the position of substitution on the menthane unit. The permeabilities of the 1,8-, 2,8-, and 1,2-isomers were in the approximate ratio of 1:2:4 for each gas at 23°C. Also, this ratio was observed to hold from 23 to 80°C. for carbon dioxide. Since the diffusion constants were found to be in the same ratio, the gas solubilities were essentially identical for the three isomeric polymers. Therefore, the permeability data could be related directly to the steric configurations of the polymers and were consistent with the hypothesis that the permeation process is controlled primarily by the degree of chain packing. Activation energy data were interpreted as an indication that the diffusion mechanism is similar for each of the isomers. In addition, the relationship of permeability, density, and glass transition temperature to steric configuration of the isomeric polymers was discussed.
    Additional Material: 2 Ill.
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  • 6
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of new aromatic polyethers have been prepared by solution condensation polymerization. The synthesis involves the condensation of a dialkali metal salt of a dihydric phenol with an “activated” or negatively substituted aromatic dihalide in an anhydrous dipolar aprotic solvent at elevated temperatures. The reaction is rapid, free of side reactions, and yields polymers of excellent color. Bakelite polysulfone can be prepared in this manner by reaction of the disodium salt of bisphenol A with 4,4′-dichlorodiphenyl sulfone in dimethyl sulfoxide (DMSO). Only dipolar aprotic solvents are useful for conducting the polymerization. Of these, DMSO and Sulfolane (tetrahydrothiophene 1,1-dioxide) are the most effective. Water or other competing nucleophiles must be absent if high molecular weight is to be obtained. Besides providing the necessary solubility, this highly polar solvent is believed to be essential in providing the rapid polymerization rates observed. The rates are further found to depend on the basicity of the bisphenol salt and upon the electron-withdrawing power of the activating group in the dihalide. As is usual for this type of reaction, the difluorides are found to be more reactive than the corresponding dichlorides. Most of the polyethers are amorphous, rigid, tough thermoplastics with high second-order transitions (Tg). Thermal stability and electrical properties are noteworthy. These and other properties are described for polysulfone, and glass transitions are given for a selected list of the other polyethers.
    Additional Material: 4 Ill.
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  • 7
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal stability and degradation process for a specific poly(aryl ether) system have been studied. In particular, the polymer which is available from Union Carbide Corporation as Bakelite polysulfone has been examined in detail. Polysulfone can be prepared from 2,2-bis(4-hydroxyphenyl)propane and 4,4′-dichlorodiphenyl sulfone by nucleophilic aromatic substitution. Because of a low-temperature transition at - 100°C. and a glass transition at 195°C., polysulfone retains useful mechanical properties from -100°C. to 175°C. A number of experimental methods were utilized to study the thermal decomposition process for this polymer system. Polysulfone gradually degraded in vacuum above 400°C. as demonstrated by mass spectrometry. Thermogravimetric analysis in argon, air, or high vacuum indicated that rapid decomposition began above 460°C. From gas chromatography, mass spectrometry and repeated laboratory pyrolyses, a number of products from polymer decompositions were identified. The most important degradation process in vacuum or inert atmosphere was loss of sulfur dioxide. Several model compounds representative of portions of poly(aryl ether) molecules were synthesized and the relative thermal stabilities determined. Possible mechanisms for pure thermal decomposition of polysulfone were derived from the product analyses, model studies, and consideration of bond dissociation energies.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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