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Molecular Dynamics Study on the Stress Concentration in Polymer Networks with Dangling Chains
Xuan Wang1, Shuangliang Zhao1,2, Xiaofei Xu1
1State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China.
The Journal of Physical Chemistry. B
|April 26, 2024
Summary
Dangling chain defects in polymer network materials (PEMs) can alleviate stress by dissipating energy. Stress concentrates near defect joints, especially at network edges, with effects varying by defect ratio.
Area of Science:
- Materials Science
- Polymer Chemistry
- Mechanical Engineering
Background:
- Structural defects in polymer network materials (PEMs) lead to stress concentration, affecting mechanical properties.
- Dangling chain defects are a common issue in PEMs, influencing their performance.
Purpose of the Study:
- To investigate the impact of dangling chain defects on stress concentration in PEMs.
- To analyze how defect ratio and proximity influence stress distribution.
Main Methods:
- Coarse-grained molecular dynamics simulations were employed.
- Graph theory was used to calculate stress distributions on the network structure.
- The effects of defect ratio (ϕ) and distance from defects were considered.
Main Results:
- Dangling chains were found to alleviate stress by dissipating internal energy.
- Stress concentration consistently occurred near the joint segments between dangling chains and the bare network.
- The concentration effect was significant near network edges, with varying stress localization on dangling chains versus the bare network based on defect ratio (ϕ).
Conclusions:
- Dangling chain defects can mitigate stress in PEMs.
- The interplay between defect ratio and network structure dictates stress concentration patterns.
- Understanding these defect-induced stress behaviors is crucial for designing robust polymer network materials.
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