Molecular forces and elastic constants of polyethylene single crystals
- 1 October 1967
- journal article
- research article
- Published by Taylor & Francis in Journal of Macromolecular Science, Part B
- Vol. 1 (3), 445-458
- https://doi.org/10.1080/00222346708212851
Abstract
Polyethylene has an orthorhombic lattice for which nine elastic constants exist; they are obtained in terms of the intra- and intermolecular forces. Constants involved in the 6-12 Lennard-Jones potential approximating the London dispersion type of van der Waals' forces are obtained by computing the crystal potential energy and comparing it with the cohesive energy. First and second nearest-neighbor interactions are considered to establish relationship between the elastic constants and the interaction constants. The latter are obtained in terms of the C—C bond, stretching, bending, and repulsive force constants and the L-J potential constants. A limited type of central force assumption is applied. Values of Young and shear moduli are obtained along the three axes. The value along the chain compares with the experimentally determined and calculated values for oriented polyethylene. Young's modulus along the lateral direction is of the order of Young's modulus of bulk polyethylene, showing that intermo-lecular forces are the ones that determine the Young modulus of bulk polyethylene.Keywords
This publication has 11 references indexed in Scilit:
- Elastic moduli of oriented polymers. I. The simple helix, polyethylene, polytetrafluoroethylene, and a general formulaJournal of Polymer Science, 1962
- Experimental determination of the elastic modulus of crystalline regions in oriented polymersJournal of Polymer Science, 1962
- A study of the elastic modulus and extensibility of the crystalline regions in highly oriented polymersJournal of Polymer Science, 1958
- The Elastic Constants of CrystalsPublished by Elsevier ,1958
- Physical Properties of Crystals: Their Representation by Tensors and MatricesPhysics Today, 1957
- A note on single crystals in polymers: Evidence for a folded chain configurationPhilosophical Magazine, 1957
- Some factors affecting the solubility of polymersJournal of Chemical Technology & Biotechnology, 1953
- Further investigations of solid n -paraffins (Repulsion potential and compressibility)Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1941
- The van der Waals potential and the lattice energy of a n — CH 2 chain molecule in a paraffin crystalProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1936
- On the calculation of certain crystal potential constants, and on the cubic crystal of least potential energyProceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 1925