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Published on: September 26, 2016
The significant structure theory applied to amorphous and crystalline polyethylene
1Department of Chemistry, University of Utah, Salt Lake City, Utah 84112.
Summary
Researchers applied significant structure theory to polyethylene, developing a partition function to calculate thermodynamic and transport properties for amorphous and crystalline states. Results align well with experimental data, marking a novel approach in polymer property calculations.
Area of Science:
- Polymer Physics
- Materials Science
- Statistical Mechanics
Background:
- The significant structure theory of liquids provides a framework for understanding the behavior of matter.
- Polyethylene exists in both amorphous and crystalline forms, exhibiting distinct physical properties.
- Previous theoretical models often lacked a comprehensive approach considering both volume and temperature dependencies for polymer properties.
Purpose of the Study:
- To apply the significant structure theory to analyze amorphous and crystalline polyethylene.
- To develop a partition function for polyethylene based on this theory.
- To calculate and compare thermodynamic and transport properties with experimental data.
Main Methods:
- Utilized the significant structure theory, incorporating solid-like, gas-like structures, and positional degeneracy.
- Derived a partition function dependent on volume, temperature, and composition.
- Calculated thermodynamic properties (e.g., Helmholtz free energy) and transport properties for amorphous polyethylene, and thermodynamic properties for crystalline polyethylene.
Main Results:
- Successfully developed a partition function applicable to both amorphous and crystalline polyethylene.
- Calculated thermodynamic and transport properties for amorphous polyethylene.
- Calculated thermodynamic properties for crystalline polyethylene, showing reasonable agreement with experimental values.
Conclusions:
- The significant structure theory is a viable model for describing the properties of polyethylene.
- The developed partition function enables accurate prediction of polymer properties.
- This study represents a novel, detailed calculation of polymer properties using a volume- and temperature-dependent partition function.
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