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Updated: Oct 1, 2025
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Ethylene Polymerizations Using Parallel Pressure Reactors and a Kinetic Analysis of Chain Transfer Polymerization
Published on: November 27, 2015
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Nonequilibrium free energy during polymer chain growth
Michael Bley1, Joachim Dzubiella1
1Applied Theoretical Physics-Computational Physics, Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder Strasse 3, D-79104 Freiburg, Germany.
The Journal of Chemical Physics
|March 2, 2022
Summary
Fast polymerization creates nonequilibrium structures with excess free energy (ΔFneq) in polymer chains and monomers. This excess energy non-monotonically changes with chain length and time, driven by monomer density and polymer shape.
Area of Science:
- Thermodynamics
- Polymer Science
- Statistical Mechanics
Background:
- Recent studies report nonequilibrium behavior in fast diffusion-influenced polymerization.
- Nonequilibrium structures are theoretically associated with excess free energy above equilibrium Helmholtz free energy.
Purpose of the Study:
- To investigate the nonequilibrium thermodynamics of chain-growth polymerization.
- To quantify the excess free energy in fast polymerization processes.
Main Methods:
- Off-lattice, reactive Brownian dynamics computer simulations.
- Approximative statistical mechanics.
- Relative entropy concepts (Gibbs-Shannon and Kullback-Leibler).
Main Results:
- Increased nonequilibrium free energies (ΔFneq) of several kBT were observed for fast-growing polymers compared to equilibrium chains.
- ΔFneq exhibited non-monotonic behavior with respect to the degree of polymerization and time.
- Excess free energy initially arises from inhomogeneous monomer density profiles and later from polymer conformations.
Conclusions:
- Fast polymerization leads to significant excess free energy stored in monomer density and polymer structure.
- The study implies nontrivial relaxation kinetics and energy restoration during post-polymerization equilibration.
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