Enhancing the Toughness of Epoxy Resin through Interface Strengthening <italic style="font-style: italic">via</italic> Chain Entanglement and Covalent Bonding

Yu-Chen Wu; Yong-Peng Wang; Meng-Zhu Liu; Hai-Bo Zhang; De-Wu Song; Yi-Long Wang; Xiao Sun; Meng-Xuan Wu; He-Xin Jing; Yu-Long Han

doi:10.1007/s10118-025-3538-9

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Enhancing the Toughness of Epoxy Resin through Interface Strengthening via Chain Entanglement and Covalent Bonding

RESEARCH ARTICLE | Updated：2026-02-13

- Enhancing the Toughness of Epoxy Resin through Interface Strengthening via Chain Entanglement and Covalent Bonding
- Chinese Journal of Polymer Science Vol. 44, Issue 3, Pages: 869-881(2026)
- Affiliations：
  
  a.College of Materials Science and Engineering, Jilin University of Chemical Technology, Jilin 132022, China
  b.Jilin Chemical Fiber Group Co., LTD., Jilin 132000, China
  c.College of Chemistry, Jilin University, Changchun 130012, China
- Author bio：
  
  wyp4889@163.com
- Funds：
- DOI：10.1007/s10118-025-3538-9
  CLC：
- Received：24 November 2025，
  
  Accepted：16 December 2025，
  
  Online First：04 February 2026，
  
  Published：15 March 2026
- Accepted：
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Wu, Y. C.; Wang, Y. P.; Liu, M. Z.; Zhang, H. B.; Song, D. W.; Wang, Y. L.; Sun, X.; Wu, M. X.; Jing, H. X.; Han, Y. L. Enhancing the toughness of epoxy resin through interface strengthening via chain entanglement and covalent bonding. Chinese J. Polym. Sci. 2026, 44, 869–881

Yu-Chen Wu, Yong-Peng Wang, Meng-Zhu Liu, et al. Enhancing the Toughness of Epoxy Resin through Interface Strengthening via Chain Entanglement and Covalent Bonding[J]. Chinese Journal of Polymer Science, 2026, 44(3): 869-881.
Wu, Y. C.; Wang, Y. P.; Liu, M. Z.; Zhang, H. B.; Song, D. W.; Wang, Y. L.; Sun, X.; Wu, M. X.; Jing, H. X.; Han, Y. L. Enhancing the toughness of epoxy resin through interface strengthening via chain entanglement and covalent bonding. Chinese J. Polym. Sci. 2026, 44, 869–881 DOI： 10.1007/s10118-025-3538-9.

Yu-Chen Wu, Yong-Peng Wang, Meng-Zhu Liu, et al. Enhancing the Toughness of Epoxy Resin through Interface Strengthening via Chain Entanglement and Covalent Bonding[J]. Chinese Journal of Polymer Science, 2026, 44(3): 869-881. DOI： 10.1007/s10118-025-3538-9.

摘要

A novel phenolphthalein-based poly(aryl ether sulfone) (PPES-TA) reactive epoxy toughener with rigid-flexible segments is proposed. Fatty acid chains and physical entanglement synergistically create optimal free volume

while the combined physical entanglement and chemical crosslinking network markedly enhances toughness and strength.

Abstract

Poly(aryl ether sulfone) with fatty-acid side chains that crosslink with epoxy resin improves the interfacial compatibility between poly(aryl ether sulfone) and epoxy resin. Hydroxyl-terminated phenolphthalein-based poly(aryl ether sulfone) (PPES-OH) was blended with fatty-acid side-chain-modified phenolphthalein-based poly(aryl ether sulfone) (PPES-TA)

with the goal of further enhancing the toughening effect on epoxy resin. In this study

PPES-OH

PPES-TA

and a composite poly(aryl ether sulfone) (PESP-TA) were synthesized. Their molecular structures and thermal properties were characterized using proton nuclear magnetic resonance spectroscopy (

H-NMR spectroscopy)

thermogravimetric analysis (TGA)

and differential scanning calorimetry (DSC). Subsequently

PPES-OH

PPES-TA

and PESP-TA were introduced into the anhydride-cured epoxy system to evaluate their toughening effects on epoxy resin. The curing behavior of the epoxy resin blends was investigated using DSC

which also enabled the exploration of the corresponding curing mechanisms. The thermal and mechanical properties of the toughened systems were characterized. Scanning electron microscopy (SEM) was used to observe the impact fracture surfaces of the resin

which rev

ealed ‘fish-scale’ structures and shear bands in the resin system after curing. These findings demonstrate that similar thermoplastic chains become entangled with one another

forming additional physical cross-links. This enhanced the interfacial compatibility between the thermoplastic and thermoset resins

which

in turn

significantly improved the impact toughness and elongation at break of the system. In summary

PESP-TA has emerged as a reactive thermoplastic toughening agent that is feasible for preparation and has significant practical application potential.

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Enhancing the Toughness of Epoxy Resin through Interface Strengthening via Chain Entanglement and Covalent Bonding

DOI：10.1007/s10118-025-3538-9

摘要

Abstract

关键词

Keywords

references