Molecular Dynamics Study of Polyurethane and KH550/SiO2 in Enhancing Epoxy Resin (EP) Mechanical Properties

Zhonghe Tong; Rui Qiu; Shaoxu Cai; Guozhi Lin; Haonan Xie; Tianyan Jiang; Maoqiang Bi

doi:10.1021/acs.langmuir.5c01077

Molecular Dynamics Study of Polyurethane and KH550/SiO₂ in Enhancing Epoxy Resin (EP) Mechanical Properties

Langmuir. 2025 Jul 3. doi: 10.1021/acs.langmuir.5c01077. Online ahead of print.

Authors

Zhonghe Tong¹, Rui Qiu¹, Shaoxu Cai², Guozhi Lin¹, Haonan Xie¹, Tianyan Jiang¹, Maoqiang Bi¹

Affiliations

¹ School of Electrical and Electronic Engineering, Chongqing University of Technology, Chongqing 400054, China.
² College of Civil Engineering, Fuzhou University, Fuzhou 350108, China.

PMID: 40607939
DOI: 10.1021/acs.langmuir.5c01077

Abstract

To enhance the mechanical properties of epoxy resin (EP), this study utilizes polyurethane (PU) and KH550/SiO₂ nanoparticles as synergistic modifiers to develop an epoxy resin composite model. In this paper, five models are established, namely: EP, PU-EP, SiO₂-SR, KH550/SiO₂-EP, and KH550/SiO₂-PU-EP model. The mechanism of PU and KH550/SiO₂ synergistic modification of EP mechanical properties is systematically studied through analyses of the cohesive energy density, free fraction volume, radius of gyration, radial distribution function, hydrogen bonding, and pull-out simulations. The results show that SiO₂ nanoparticles modified with the KH550 coupling agent enhance the interaction energy between SiO₂ and the EP matrix in the composite. At different temperatures (300-450 K), both fillers demonstrated the ability to lower the free fractional volume within EP composites. Additionally, they enhanced the quantity of hydrogen bonds, shortened the hydrogen bond distances within the system, and increased the proportion of hydrogen bonds exhibiting higher angles. Among them, KH550-SiO₂/UP/EP has the most obvious improvement effect on the system, indicating that KH550/SiO₂ and PU synergistically modified epoxy resin can improve the mechanical properties of the composites. At 300 K, the Young's modulus, shear modulus, bulk modulus, and bulk modulus/shear modulus of KH550-SiO₂/UP/EP system are 8.12%, 7.03%, 16.05%, and 8.43% higher than those of EP system, respectively. At 450 K, it increased by 18.26%, 17.30%, 23.87%, and 27.57%, respectively. The findings of this study are anticipated to offer valuable insights for the design and performance enhancement of epoxy resin composites.