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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 31 (1966), S. 100-104 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    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 changes that are observed under magnification when a single polyvinyl chloride particle is immersed in a drop of diluent and slowly heated have been explained on the basis of a three-dimensional network system in which the polymer crystallites act as junction points for the network. The existence of a temperature at which a sharp gel-to-sol transformation is observed has been attributed to the melting of the polymer crystallites. The temperature at which this transformation occurs was found to be rate-independent, reproducible, and characteristic for each polyvinyl chloride-diluent system. At this apparent melting temperature, the volume fraction of the diluent in the swollen particle was shown to approach unity. These findings made it possible, for the first time, to apply to polyvinyl chloride-diluent systems Flory's treatment of the effect of diluents on the crystal melting temperature of semicrystalline polymers. The apparent melting temperatures of polyvinyl chloride with 27 diluents were determined by the above method. The interaction parameter χ for each of the diluents used had been previously reported by Doty and Zable. A linear relationship was obtained when the reciprocal melting temperature was plotted against (1-χ)/V1 for all of the above polyvinyl chloride-diluent systems (V1 is the molar volume of the diluent at the melting temperature). From this plot the values for the extrapolated melting temperature of pure polyvinyl chloride and for the average heat of fusion were calculated and found to be 176°C. and 656 cal./mole, respectively. Based on these findings a micromethod has been developed which can be used to determine the parameter χ of a diluent with polyvinyl chloride from a single determination of this apparent melting temperature. This method also yields the value for the energy of interaction parameter B.
    Additional Material: 7 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 20 (1976), S. 3005-3016 
    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: A new method for predicting elastic moduli M of heterogeneous polymer compositions is proposed. It is based on a phenomenological adjustment between parallel and series models for upper and lower bound moduli MU and ML. Thus, \documentclass{article}\pagestyle{empty}\begin{document}$$ M = \phi _H ^n (n\phi _S + 1)(M_U - M_L ) + M_L $$\end{document} where φH is the volume fraction of hard phase, φS is the volume fraction of soft phase, and n is the only adjustable parameter since the upper and lower bound moduli are given by \documentclass{article}\pagestyle{empty}\begin{document}$$ M_U = \phi _H M_H + \phi _S M_S $$\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$$ M_L = (\phi _H /M_H + \phi _S /M_S )^{ - 1} $$\end{document} where MH and MS are the moduli of the pure hard and soft phases, respectively. Predicted values of M are in agreement with measured values in a number of systems which include polyblends and composite materials of fixed morphology. The significance of n is discussed relative to concentrations in the area of a phase transition for the polyblends or relative to phase morphology in the case of fixed morphology compositions. Interestingly, the relationship, by analogy, is in agreement with measured values of polyblend melt viscosities.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 15 (1971), S. 2471-2485 
    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 solvent swelling of unidirectional rubber-fiber composites was studied. The amount of matrix swelling was constrained to the extent that would be predicted from the thermodynamic theories of elasticity and polymer-solvent interaction. The geometry of swelling was found to be orthotropic in nature. A simple trigonometric function was derived to relate linear deformation due to swelling to the angle which the direction of its measurement makes with the fiber direction. The validity of the derivation was demonstrated experimentally. Considering swelling to be the imposition of tensile forces of equal magnitude in all directions, and considering a swelling-induced linear deformation to be analogous to a tensile compliance, a simple set of relationships between elastic parameters and their direction of measurement was derived: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {\frac{1}{{E_\theta }} = \frac{{\cos ^2 \theta }}{{E_L }} + \frac{{\sin ^2 \theta }}{{E_T }}} \\ {G_\theta = G_{LT} } \\ {v_\theta = v_{LT} \frac{{E_\theta }}{{E_L }}} \\ {\eta _\theta = E\left( {\frac{1}{{E_T }} - \frac{1}{{E_L }}} \right){\rm }\cos \theta {\rm sin}\theta } \\ \end{array}$$\end{document} where Eθ, Gθ, vθ, and ηθ are Young's modulus, shear modulus, Poisson's ratio, and the shear coupling ratio measured in a longitudinal transverse plane at an angle with the fiber direction, respectively, and EL, GLT, and θLT are the longitudinal Young's modulus, the longitudinal transverse shear modulus, and the longitudinal transverse Poisson ratio, respectively. Further simplifying the case of combined transverse isotropy and special orthotropy was the conclusion that 1/GLT = 1/ET + (1 + 2vLT)/EL. The relationships for G and E were experimentally demonstrated.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 57 (1962), S. 1-11 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The solvent power of a variety of diluents with polyvinyl chloride was evaluated in terms of the polymer - diluent interaction parameter χ and heat of mixing parameter B by means of a micromethod reported in the first part of this series. Among the diluents investigated are esters of phthalic, fumaric and maleic acids, alkyl-substituted benzenes, and condensed and conjugated aromatic ring systems. Relationships between solvency and diluent structure were sought in terms of the intermolecular forces involved in polymer - diluent associations. A condition found necessary for good solvency is that both the dispersion and dipolar forces acting between solvent molecules be similar in strength to the corresponding forces acting between polymer macromolecules. Steric hindrance of the carbonyl dipoles in the ester molecules, or of the aromatic nuclei in the hydrocarbon molecules, has a pronounced effect on the values of B. The extent of resonance interactions in the hydrocarbon molecules influence their solvent power. Where such interactions are reduced due to steric effects, solvency is also reduced.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 57 (1962), S. 13-23 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The interactions between polyethylene and a number of hydrocarbon diluents were characterized on the basis of the Flory-Huggins interaction parameter χ and the closely related heat of mixing parameter B. The evaluations of these parameters were based on Flory's statistical-thermodynamic treatment of the effect of diluents on the melting points of crystalline polymers. Necessary for each evaluation was a single microscopic determination of the depressed melting point of polyethylene in its mixture with a given diluent as indicated by the disappearance of the last visible traces of crystallinity upon slow heating. Each mixture was diluted to an extent that the volume fraction of diluent approximated unity. This permitted the use of a simplified form of the Flory equation. The data obtained from the study of thirty diluents were utilized in an attempt to correlate diluent structure with solvency. Generally, the various types of hydrocarbon diluents can be rated in the following order of increasing solvency: aromatic, alkylaromatic, aliphatic, alicyclic. In addition, it was demonstrated that the value of B for a given diluent can be reliably estimated as a function of a new parameter which is calculated from the diluent structure, density, and an estimated value of the ionization energy. This new parameter also correlates well with the solubility parameter δT.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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