Predicting water sorption and volume swelling in dense polymer systems via computer simulation

Area of Science:

• Materials Science and Engineering
• Computational Chemistry
• Polymer Science

Background:

• Accurate modeling of polymer networks is crucial for understanding material properties.
• Existing methods for generating cross-linked polymer structures may lack realism.
• Predicting water absorption and swelling is essential for adhesive performance evaluation.

Purpose of the Study:

• To develop and apply atomistic models for amorphous polyamide 6 (PA-6) and a DGEBA+IPD epoxy adhesive system.
• To introduce a novel approach for generating realistic cross-linked polymer networks by incorporating chemical reaction kinetics.
• To calculate equilibrium water content and swelling ratios for PA-6 and the DGEBA+IPD network under various thermodynamic conditions.

Main Methods:

• Generation of atomistic model structures for PA-6 and the DGEBA+IPD adhesive system.
• A new hybrid simulation method combining molecular dynamics with accelerated test particle insertion.
• Incorporation of chemical reaction kinetics for more realistic cross-linked network generation in the adhesive system.

Main Results:

• Successful generation of atomistic models for amorphous PA-6 and the DGEBA+IPD adhesive.
• Calculated equilibrium water content and swelling ratios show reasonable agreement with experimental data.
• The novel network generation approach yields realistic structures, validated by comparison with PA-6 simulations.

Conclusions:

• The developed hybrid simulation method accurately predicts the behavior of polymer networks, including water absorption and swelling.
• The new approach for generating cross-linked polymer networks based on reaction kinetics provides more realistic models.
• These findings contribute to a better understanding and design of advanced polymer materials and adhesive systems.