Molecular Dynamics Simulation for the Effect of Fluorinated Graphene Oxide Layer Spacing on the Thermal and Mechanical Properties of Fluorinated Epoxy Resin.

Qijun Duan,Xinyu Yang,Qing Xie,Jun Xie,Guowei Xia,Zhengyong Huang,Chaoxuan Xiao

doi:10.3390/nano11051344

Qijun Duan, Xinyu Yang + Show 5 more

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https://doi.org/10.3390/nano11051344

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Abstract

Traditional epoxy resin (EP) materials have difficulty to meet the performance requirements in the increasingly complex operating environment of the electrical and electronic industry. Therefore, it is necessary to study the design and development of new epoxy composites. At present, fluorinated epoxy resin (F-EP) is widely used, but its thermal and mechanical properties cannot meet the demand. In this paper, fluorinated epoxy resin was modified by ordered filling of fluorinated graphene oxide (FGO). The effect of FGO interlayer spacing on the thermal and mechanical properties of the composite was studied by molecular dynamics (MD) simulation. It is found that FGO with ordered filling can significantly improve the thermal and mechanical properties of F-EP, and the modification effect is better than that of FGO with disordered filling. When the interlayer spacing of FGO is about 9 Å, the elastic modulus, glass transition temperature, thermal expansion coefficient, and thermal conductivity of FGO are improved with best effect. Furthermore, we calculated the micro parameters of different systems, and analyzed the influencing mechanism of ordered filling and FGO layer spacing on the properties of F-EP. It is considered that FGO can bind the F-EP molecules on both sides of the nanosheets, reducing the movement ability of the molecular segments of the materials, so as to achieve the enhancement effect. The results can provide new ideas for the development of high-performance epoxy nanocomposites.

Highlights

Epoxy resin reacts with a curing agent to form a polymer with a three-dimensional network structure
In the process of molecular simulation, the strain is applied to different directions and repeated many times
The model of ordered filled fluorinated graphene oxide (FGO) nanosheets was constructed, and the effect of FGO nanosheets spacing on the thermal and mechanical properties of fluorinated epoxy resin composites was studied. It shows that the orderly filling of FGO can significantly improve the static elastic modulus, Tg, Coefficient of Thermal Expansion (CTE), and thermal conducductivity (TC) of the composite materials

Summary

Introduction

Epoxy resin reacts with a curing agent to form a polymer with a three-dimensional network structure. The cured product has excellent electrical insulation, mechanical properties, and chemical corrosion resistance. As the operating conditions of epoxy resin materials become increasingly complex, higher requirements have been put forward for their thermal, mechanical, and insulation properties [5,6]. In recent years, fluorinated epoxy resin (F-EP) has gradually attracted researchers’ attention due to excellent insulation and dielectric properties coming from the extremely strong electronegativity of fluorine and the high bond energy of C-F bond [7,8,9]. The mechanical strength, heat resistance, and thermal conductivity of F-EP materials cannot meet the requirements of high voltage insulation materials, which has become a key factor restricting its further application. It is necessary to improve its thermal and mechanical properties

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Discussion

Conclusion