Open AccessThe Significant Structure Theory Applied to Amorphous and Crystalline Polyethylene
Author(s) -
Shangkeng Ma,
Henry Eyring,
Mu Shik Jhon
Publication year - 1974
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.71.8.3096
Subject(s) - amorphous solid , helmholtz free energy , polyethylene , thermodynamics , materials science , partition function (quantum field theory) , volume (thermodynamics) , chemistry , crystallography , physics , quantum mechanics , composite material
The significant structure theory of liquids has been applied to amorphous and crystalline polyethylene. In this theory the amorphous state, like liquids in general, is assumed to have solid-like structure, gaslike structure, and positional degeneracy which arises from the motion of kinetic segments and from the libration of CH2 units. This concept leads to a partition function giving the Helmholtz free energy in terms of volume, temperature, and composition.Thermodynamic and transport properties are calculated for amorphous polyethylene. The thermodynamic properties are also calculated for the crystalline solid. The calculated results are in reasonable agreement with the experimental values. No such detailed calculations of polymer properties from a partition function, depending on both volume and temperature, have been previously attempted.