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  • 1
    Electronic Resource
    Electronic Resource
    The relationship between nonexponential relaxation and molecular stiffness in aromatic model compounds (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 5254-5256 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The α relaxation of a series of ether–ketone model compounds was studied to quantify the effect of molecular stiffness on the Kohlrausch–Williams–Watts stretching exponential. The obtained values decrease with increasing stiffness and are within the theoretical bounds predicted for systems with spatial dimensionality varying from 2 to 1. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.481094
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  • 2
    Electronic Resource
    Electronic Resource
    Relaxation behavior in model compounds of poly(aryl-ether-ketone-ketone) as revealed by dielectric spectroscopy (1999)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 110 (1999), S. 10134-10140 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The relaxation behavior of a series of ether-ketone oligomers, considered as model compounds of poly(ether-ketone-ketone), was studied by means of dielectric spectroscopy. The dynamics of the α relaxation of ether-ketone model compounds as compared with that of poly(arylether-ketone-ketone) (PEKK) (50/50), shows up differences which can be attributed to the variation of inter- and intramolecular correlations with the chain length. Model compounds exhibit a nearly similar degree of cooperativity regardless the differences in Tg values. The PEKK (50/50) polymer exhibits stronger cooperativity than the oligomers suggesting that in poly(ether-ketone-ketone)s molecular motions above Tg extend to more than one monomeric unit. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.478886
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  • 3
    Electronic Resource
    Electronic Resource
    Conformation and Flexibility Parameter of Polymeric Chains (1973)
    s.l. : American Chemical Society
    Macromolecules 6 (1973), S. 111-113 
    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/ma60031a018
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  • 4
    Electronic Resource
    Electronic Resource
    Anomaly in the Molecular Weight Dependence of Surface Tension of Molten Polyethers and Polyesters. Evidence of Chain Folding? (1974)
    s.l. : American Chemical Society
    Macromolecules 7 (1974), S. 255-256 
    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/ma60038a020
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  • 5
    Electronic Resource
    Electronic Resource
    Structure-dependent enthalpy relaxation at the glass transition of polystyrenes (1986)
    s.l. : American Chemical Society
    Macromolecules 19 (1986), S. 901-904 
    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/ma00157a071
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  • 6
    Electronic Resource
    Electronic Resource
    Excess entropies and related quantities in glass-forming liquids (1980)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 84 (1980), S. 3307-3312 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100461a034
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  • 7
    Electronic Resource
    Electronic Resource
    Mechanical properties of heterocyclic polymer networks (1993)
    Springer
    Colloid & polymer science 271 (1993), S. 322-327 
    Details
    ISSN: 1435-1536
    Keywords: Young's modulus ; bulk modulus ; Poisson's ratio ; linear expansivity ; isocyanoureate cycles ; oxazolidone cycles ; network density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Heterocyclic networds prepared by copolymerization of oligomeric epoxy rubber (ER) with different amounts of hexamethylene diisocyanate (HMDI) were characterized by room-temperature static Young's and bulk moduli, as well as by measurements of dynamic Young's modulus and linear thermal expansivity in the temperature interval 293–503 K. It was concluded that the major factor affecting thermoelastic properties of these networks is the relative content of three-arm, six-membered isocyanoureate rings which determine the apparent overall network density, and of two-arm, five-membered oxazolidone rings which act as a sort of “internal diluent”.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00657414
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  • 8
    Electronic Resource
    Electronic Resource
    Thermodynamics of polymer deformation in simple shear. Part I: Polymer networks (1993)
    Springer
    Colloid & polymer science 271 (1993), S. 539-547 
    Details
    ISSN: 1435-1536
    Keywords: Thermodynamics ; thermoelasticity ; simple shear ; polymer networks ; deformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Thermodynamic analysis of the relevant equation of state was used to develop a theoretical description of deformation behavior of polymer networks in simple shear. According to the theory, the essential feature of polymer networks subject to simple shear is the absence of “thermoelastic inversion” phenomenon which is typical for the case of the uniaxial extension. Application of deformation calorimetry to study the thermoelastic response of natural rubber to uniaxial stretching and simple shear regimes of deformation revealed both adequate correspondence of theory and experiment, as well as coincidence of material constants of natural rubber derived from these two independent experiments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00657984
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  • 9
    Electronic Resource
    Electronic Resource
    Thermodynamics of polymer deformation in simple shear. Part II. Polymeric glasses (1993)
    Springer
    Colloid & polymer science 271 (1993), S. 548-553 
    Details
    ISSN: 1435-1536
    Keywords: Thermodynamics ; thermoelasticity ; uniaxial stretching ; simple shear ; polymeric glasses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A theoretical description of deformation behavior of polymeric glasses in simple shear regime was developed from thermodynamic analysis of relevant starting equations of state. In contrast to the linear dependence of deformation heat on the elongation characteristic for a uniaxial stretching regime, in the case of a simple shear regime a parabolic dependence of deformation heat on deformation parameter was predicted. Theoretical predictions on deformation behavior of polymeric glasses in both uniaxial stretching and in simple shear regimes were experimentally verified by deformation calorimetry technique on two polystyrene samples with different molecular weights. Experimental data were found to obey theoretical equations within the limits of elastic deformations, and a good agreement was established between material constants derived from independent experiments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00657985
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  • 10
    Electronic Resource
    Electronic Resource
    Structure-property relationships for carbochain fluoropolymers (1985)
    Springer
    Colloid & polymer science 263 (1985), S. 322-327 
    Details
    ISSN: 1435-1536
    Keywords: Carbochain fluoropolymers ; melting entropy ; melt compressibility ; cell model ; chain stiffness ; free volume fraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF) and polychlorotrifluoroethylene (PCTFE) were studied by differential calorimetry at normal pressure in the temperature interval 130–555 K, and by pressure dilatometry in the temperature interval 303–545 K and in the pressure range 14–70 MPa. Pressure derivatives of the melting temperature,dT m/dP, were used to calculate the “true” melting entropy ΔS m from the Clausius-Clapeyron equation, while equilibrium values of the melt specific volume were treated according to the Simha-Somcynsky cell theory. Comparison of the experimental data for PVF, PVDF and PCTFE with pertinent published data for polyethylene (PE) and polytetrafluoroethylene (PTFE) showed that a steady decrease of ΔS m and of the conformational contribution to ΔS m reflects the increase of the equilibrium chain stiffness as the hydrogen atoms of the hydrocarbon chain (PE) are substituted with bulkier fluorine and/or chlorine atoms (PCTFE, PTFE), while a concomitant drop of the pressure reducing parameter from the cell model and an increase of melt compressibility and the derivative,dT m/dP, should be attributed to the increase of the free volume fraction of the melt in the series, PE to PTFE.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01412248
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