Journal ArticleDOI
Struktur- und Konformationsberechnung in Polymeren: II. Idealkristall und Defektzustand (Bündelmodell) von Polyäthylen
G. Wobser,S. Blasenbrey +1 more
- Vol. 241, pp 985-993
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TLDR
In this article, a potential is given and discussed which has been fitted in such a way that it is also suitable for the calculation of the cohesion energy and the lattice parameters of the ideal polyethylene crystal.Abstract:
ZusammenfassungDas in Teil I angegebene und diskutierte Potential ist so angepaßt, daß es auch die Kohäsionsenergie und die Gitterparameter des Polyäthylenidealkristalls richtig wiedergibt. Die dazu ausgeführten Rechnungen werden hier mitgeteilt. Zusätzlich konnte gezeigt werden, daß bei beliebiger Wahl der Potentialkonstanten in einem physikalisch sinnvollen Bereich die intermolekulare Energie bezüglich des Einstellwinkels θ nur zwischen 45,5° und 47,5° ein Minimum besitzt.Mit dem angegebenen Potential wurden für Polyäthylen die anisotropen elastischen Konstantencik und Koeffizientensik mit derBornschen Gittertheorie berechnet. DieReußsche Mittelung für isotrope Medien liefert eine gute Übereinstimmung mit den experimentellen Ergebnissen.Die in die kooperativ statistische Behandlung eines Kettenbündels eingehenden Parameter (Energie und Volumen) eines Segmentpaares aus gleichen Kinken (110-Typ) wurden durch Minimalisierung der intermolekularen Energie berechnet. Es ergibt sich eine gute Übereinstimmung mit den seither benützten Werten.SummaryIn part I a potential is given and discussed which has been fitted in such a way that it is also suitable for the calculation of the cohesion energy and the lattice parameters of the ideal polyethylene crystal. Here these calculations are given in detail. Additionally, it could be shown that at arbitrary choice of the potential constants in the physical possible region the setting angle is θ always situated between 45,5° and 47,5°.The given potential has been used to calculate the elastic constantscik and coefficientssik for the polyethylene single crystal by means ofBorn's lattice dynamics. TheReuss average procedure for isotropic bodies gives a good agreement with experimental data.Some parameters (energy and volume) being important in the cooperative statistical treatment of chain bundles have been calculated for pairs of kinked segments by minimizing the intermolecular energy. One gets a good agreement between the calculated parameters and those derived by geometric estimations.read more
Citations
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Journal ArticleDOI
Thermodynamics of fusion of poly-β-propiolactone and poly-ϵ-caprolactone. comparative analysis of the melting of aliphatic polylactone and polyester chains
TL;DR: In this paper, the entropy of poly-β-propiolactone and poly-ϵ-caprolactone was investigated and a theoretical analysis of the constant volume entropy of melting of the polylactones and of three aliphatic polyesters was made.
Journal ArticleDOI
Deformation mechanisms in crystalline polymers
P. B. Bowden,Robert J. Young +1 more
TL;DR: The mechanisms which have been suggested to explain the deformation of crystalline polymers are reviewed in this article, where emphasis has been placed upon the type of information that can be gained from experimental observations and on the extent to which those observations are consistent with suggested deformation mechanisms and current ideas on polymer structure and morphology.
Journal ArticleDOI
Kink‐Block and Gauche‐Block Structures of Bimolecular Films
TL;DR: In this paper, the structure of monomolecular and bimolecular films has been investigated in terms of reversible kink-block and gauche-block structures of lipid layers in membranes.
Journal ArticleDOI
Molekülbewegung in Polymeren: III. Teil: Mikrostruktur und mechanische Eigenschaften
W. Pechhold,S. Blasenbrey +1 more
TL;DR: In this article, a Molekulare Theorie der Relaxationserscheinungen (α, β, γ) is given and experimentally proved for linear polyethylene.
References
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Nonbonded Potential Parameters Derived from Crystalline Hydrocarbons
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Book ChapterDOI
Heat capacities of linear high polymers
B. Wunderlich,H. Baur +1 more
TL;DR: Linear high polymers heat capacity measurements theory emphasizing simple mechanical systems and contribution of lattice vibrations was introduced in this article, where the authors proposed a heat capacity measurement theory based on the lattice vibration model.