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  • 1
    Electronic Resource
    Electronic Resource
    Viscoelastic relaxations in oxidized poly(hexamethylene sulfide) (1984)
    s.l. : American Chemical Society
    Macromolecules 17 (1984), S. 348-351 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma00133a016
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  • 2
    Electronic Resource
    Electronic Resource
    Anionic synthesis and thermal properties of poly(3,3-diethylthietane) (1989)
    Springer
    Polymer bulletin 21 (1989), S. 571-576 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary 3,3-Diethylthietane has been polymerized by means of the anionic initiators butyl lithium and naphthalene sodium. Linear poly (3,3-diethylthietane) samples have been obtained. The molecular weight of these polymers, measured by GPC, ranges from 70,000 to 241,000. The molecular weight distribution is quite narrow. Calorimetric measurements show a glass transition temperature, extrapolated to zero heating rate, of 236.7 K. The melting curves of a sample isothermally crystallized from the melt at 303 K show two different melting peaks located at 326 and 334 K, respectively. The wide angle X-ray diffractograms for poly (3,3-diethylthietane) crystallized at 303 and 330 K gave identical patterns. Microscopy and small angle light scattering observations show that the supermolecular structure corresponds to ordered spherulites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00264137
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  • 3
    Electronic Resource
    Electronic Resource
    Raman spectroscopic study of a substituted poly(phosphazene) (1991)
    Springer
    Polymer bulletin 25 (1991), S. 351-356 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Polyphosphazenes present a range of unique and fascinating physical properties, including thermotropic behaviour, which are highly dependent both on the type of substitution at the P atom in the inorganic backbone, and the thermal history of the material. Recent technological advances have allowed us to study this group of polymers using vibrational spectroscopy. Fourier transform (FT) Raman spectra have been recorded from samples of poly[bis(4-methoxy-phenoxy)phosphazene] with different thermal histories. With the aid of spectral subtraction methods, differences observed between the spectra have been related to the crystalline and mesophase content of the materials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00316905
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  • 4
    Electronic Resource
    Electronic Resource
    Polymerization of tetrahydrofuran by bifunctional cationic initiators: Terephthaloyl perchlorate (1981)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 182 (1981), S. 731-737 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The kinetics and mechanism of the polymerization of tetrahydrofuran with terephthaloyl perchlorate in methylene chloride or cyclohexane were analyzed. This polymerization produces dicationically active polymers and takes place without induction period. Propagation in both solvents proceeds as a reaction being first order in monomer, and it changes with the polarity of the solvent because ionic and covalent species take part with different growing rates. The macroester mole fractions in cyclohexane and methylene chloride are 0,99 and 0,86, respectively.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1981.021820303
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  • 5
    Electronic Resource
    Electronic Resource
    Crystallization, melting and morphology of poly(hexamethylene sulfide) (1987)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 188 (1987), S. 1205-1215 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly(hexamethylene sulfide) fractions, ranging in molecular weight from 4600 to 20000, were isothermally crystallized from the melt state in the temperature range 50-70°C. The dependence of the melting temperature on the crystallization temperature was analyzed in experiments involving low and high levels of crystallinity. The equilibrium melting temperature corresponds to 366 K and the enthalpy of fusion was found to be 40,5 cal/g (= 170 J/g). The isothermal overall crystallization rates were analyzed using dilatometric and calorimetric techniques. The Avrami exponent is an integral value, n = 3, and the crystallinity varies with increasing molecular weight from 65% to 55%. The morphology is spherulitic and it was found that the growth rate is linear in the whole range of crystallization temperatures. The temperature coefficient of the crystallization was analyzed using nucleation theory, and comparison between dilatometric and growth data revealed that the overall rate and growth rate-temperature coefficients are approximately equal.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1987.021880523
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  • 6
    Electronic Resource
    Electronic Resource
    Asymmetrically branched alkyl spacers in liquid-crystalline poly(alkylene 4,4′-terephthaloyldioxydibenzoate)s (1992)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 193 (1992), S. 2251-2258 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly[oxy-(1,4-dimethyltetramethylene)oxycarbonyl-1,4-phenyleneoxyterephthaloyloxy-1,4-phenylenecarbonyl] (1) was synthesized for the first time, and its thermal behaviour was studied by differential scanning calorimetry, thermooptical microscopy, and X-ray diffraction. The crystal to liquid-crystal and the mesophase to isotropic transition temperatures are lower by ca. 100°C than the values reported for the unsubstituted polymer. Moreover, the formation of a three-dimensional order is hindered in the case of the polymer with lateral substituents and can only be achieved by long annealing times.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1992.021930908
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  • 7
    Electronic Resource
    Electronic Resource
    Oxidation of poly(tetramethylene sulfide) (1984)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 1255-1263 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Oxidation of poly(tetramethylene sulfide) single crystals was carried out in a dispersion of distilled water at 25°C using trifluoroacetic acid and H2O2. The oxidation takes place in two different stages: the first one corresponds to preferential formation of sulfoxide groups and the second one, at higher concentrations of oxidizing agent, corresponds to formation of sulfone groups. Changes in crystallinity and melting behaviour of the intermediate polysulfones obtained were followed by X-ray diffraction and calorimetry. Changes in the heat and temperature of melting and in the morphology are related to the different stages of oxidation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1984.021850618
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  • 8
    Electronic Resource
    Electronic Resource
    Spherulitic growth rates of poly(3,3-dimethyloxetane) (1985)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 186 (1985), S. 439-447 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The morphology and growth rates of crystallized fractions of poly(3,3-dimethyloxetane) covering the range Mn = 18500 to Mn = 130000 were studied by polarized light microscopy at crystallization temperatures from 24 to 44°C. It was found that the growth rate is linear and only spherulites are formed in the temperature range examined. The growth rate-temperature coefficient was analyzed by using nucleation theory. The usual plots are linear in the whole range of crystallization temperatures, and the comparison between dilatometric and growth data revealed that the overall rate- and growth rate-temperature coefficients are approximately the same.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1985.021860222
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  • 9
    Electronic Resource
    Electronic Resource
    Polymorphism in poly(3,3-dimethyloxetane) (1985)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 186 (1985), S. 1731-1737 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A detailed study of the polymorphism of poly(3,3-dimethyloxetane) was carried out by differential scanning calorimetry and X-ray diffraction. From the relaxed melt state, two modifications, Form II (monoclinic) and Form III (orthorhombic), are separately obtained depending on crystallization temperature. When the crystallization is accomplished for a given modification, this one is stable at any temperature below its melting temperature. However, if the crystallization of a given modification is not complete, the other modification can be crystallized from the amorphous phase. Thus, a possibility of obtaining both forms exists. The kinetic and thermodynamic factors which govern this process are analyzed. The free energies were calculated and the conclusion is that modification II is thermodynamically the most stable one at all temperatures below its melting point.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1985.021860822
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  • 10
    Electronic Resource
    Electronic Resource
    Dynamic mechanical behaviour of chlorinated polyethylene (1980)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 181 (1980), S. 1349-1356 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Dynamic mechanical measurements of chlorinated polyethylenes with chlorine contents ranging from 5,4 to 31 wt.-% were carried out using a dynamic viscoelastometer. The complex modulus and loss factor were determined at four frequencies in the temperature range from -150°C to 100°C. Two relaxation processes (α and γ) were observed. The first one occurs at temperatures ranging from 21°C to 40°C, depending on the chlorine content; there is a minimum in the temperature of the α process at about 20 wt.-% of chlorine. The activation energies for this α process are higher than 100 kcal/mol, and therefore this α relaxation is considered to be different from the α relaxation in linear polyethylene. On the other hand, the α relaxation of chlorinated polyethylenes is similar to that of the parent polyethylene, taking place at temperatures ranging from -137°C to -116°C (at 3,5 Hz). The activation energies for this α process range from 14 to 26 kcal/mol (1 kcal = 4,184 kJ).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1980.021810615
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