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Entanglement Network Suppresses Toughness Deterioration in Polycarbonate at Superhigh Strain Rates
Peng Dong1, Jian-Bin Tang1, Han Shang1
1College of Polymer Science and Engineering, State Key Laboratory of Advanced Polymer Materials, Sichuan University, Chengdu, P. R. China.
Macromolecular Rapid Communications
|December 23, 2025
Summary
High molecular chain entanglement in polycarbonate (PC) improves mechanical performance at high strain rates. Increased entanglement density suppresses energy absorption deterioration, enhancing material resilience under extreme deformation.
Area of Science:
- Materials Science
- Polymer Physics
Background:
- Polycarbonate (PC) is crucial for safety applications like window glazing.
- Understanding PC mechanical behavior at superhigh strain rates is essential for material design.
Purpose of the Study:
- To investigate the influence of molecular chain entanglement on PC mechanical performance at superhigh strain rates.
- To elucidate the mechanisms behind strain rate-dependent mechanical behavior and energy dissipation.
Main Methods:
- Mechanical testing across a wide strain rate range (0.01–100 s⁻¹).
- Real-time observation using digital image correlation (DIC).
- Dynamic mechanical analysis (DMA) to assess energy dissipation properties.
Main Results:
- PC toughness increases with strain rate up to 100 s⁻¹, where stiffness and toughness deteriorate.
- DIC revealed severe stress concentration and strain localization at 100 s⁻¹.
- High entanglement density suppressed this deterioration, enhanced strain hardening, and increased energy dissipation (loss modulus and tan δ in the β-relaxation region).
Conclusions:
- Molecular chain entanglement significantly influences PC mechanical performance under extreme deformation.
- Tailoring entanglement networks can suppress energy absorption deterioration, improving material resilience.
- Enhanced energy dissipation due to entanglement is key to improved resistance to deformation.
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