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Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
Simulation of melting in crystalline polyethylene
E A Zubova1, N K Balabaev, A I Musienko
1N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygin Street, Moscow 119991, Russia. zubova@chph.ras.ru
The Journal of Chemical Physics
|June 21, 2012
Summary
Crystalline polyethylene (PE) undergoes structural phase transitions when heated, forming monoclinic and columnar phases instead of rotator phases seen in linear alkanes. This simulation reveals PE
Area of Science:
- Materials Science
- Polymer Physics
- Computational Chemistry
Background:
- Crystalline polyethylene (PE) exhibits complex phase behavior upon heating.
- Understanding these transitions is crucial for predicting material properties.
Purpose of the Study:
- To investigate the initial stages of constrained melting in crystalline polyethylene.
- To elucidate the molecular mechanisms and driving forces behind PE's structural phase transitions.
Main Methods:
- Molecular dynamics simulation of crystalline polyethylene.
- Real-time tracking of structural phase transitions (orthorhombic to monoclinic, monoclinic to columnar).
Main Results:
- Observed two distinct structural phase transitions: orthorhombic (O) to monoclinic (M), then to columnar (C).
- Identified the M phase as parallel packing of PE zigzag planes and C as an oriented melt.
- Polyethylene attempts, but fails, to form rotator phases (RI, RII) analogous to linear alkanes during transitions.
Conclusions:
- The monoclinic and columnar phases in polyethylene act as substitutes for the rotator phases found in linear alkanes.
- The study provides insights into the unique melting behavior and phase transitions of crystalline polyethylene.
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