Phantom Force Balance Procedure for Predicting the Modulus of Entangled Polymer Networks

Area of Science:

• Polymer Science
• Computational Materials Science
• Rheology

Background:

• Predicting the shear modulus of entangled polymer networks is crucial for material design.
• Existing methods like molecular dynamics (MD) simulations are computationally intensive.
• Theoretical models may not capture complex network architectures accurately.

Purpose of the Study:

• To present a novel computational phantom Force Balance, Maximum Entropy Homogenization Procedure (FB-MEHP).
• To efficiently predict the equilibrium shear modulus of entangled polymer networks.
• To validate the FB-MEHP against established simulation and theoretical methods.

Main Methods:

• Utilizing a Monte Carlo method to generate bead-spring polymer network microstructures.
• Introducing entanglements by creating tetrafunctional cross-links between adjacent network strands.
• Optimizing microstructures to their minimum free energy state for modulus calculation.

Main Results:

• FB-MEHP demonstrated near-perfect agreement with stress-relaxation MD simulations and Miller-Macosko theory (MMT).
• Computational resources required by FB-MEHP were significantly lower (4+ orders of magnitude less) than MD simulations.
• The procedure showed good agreement with experimental data for diverse polymer networks, including bottlebrush and comb-like structures.

Conclusions:

• The FB-MEHP is a computationally efficient and accurate method for predicting polymer network shear modulus.
• This procedure offers a practical tool for predicting the modulus of various polymer network architectures.
• The FB-MEHP has potential applications in designing and optimizing polymer-based materials.