Derived Coarse-Grained Potentials for Semicrystalline Polymers with a Blended Multistate Iterative Boltzmann...

Area of Science:

• Polymer Science
• Computational Chemistry
• Materials Science

Background:

• Semicrystalline polymers exhibit both amorphous and crystalline phases, posing challenges for accurate molecular modeling.
• Simulating the dynamics of the α-relaxation process requires precise representation of both phases.

Purpose of the Study:

• To develop accurate coarse-grained potentials for semicrystalline polymers using the multistate iterative Boltzmann inversion (MS-IBI) method.
• To achieve tunable control over the dynamics of the α-relaxation process.
• To investigate the impact of phase weighting on structural and dynamic accuracy.

Main Methods:

• Employed the multistate iterative Boltzmann inversion (MS-IBI) method.
• Developed a family of potentials for polyethylene by blending phase-specific potentials.
• Varied the weighting factor for the crystalline phase from 0 to 1.

Main Results:

• Optimal structural distribution accuracy was achieved with a 50% crystalline phase weight.
• A 90% crystalline phase weight yielded more accurate α-relaxation dynamics, including realistic activation energies and diffusion rates.
• High crystalline phase weighting had a minor impact on structural accuracy.

Conclusions:

• The MS-IBI method allows for accurate representation of both amorphous and crystalline phases in semicrystalline polymers.
• A balance between structural accuracy and dynamic representation can be achieved by tuning the phase weighting factor.
• This approach offers improved predictive capabilities for polymer behavior.