In this article, the effects of coupling agent, silica particle size, and particle shape on the mechanical properties of polyimide (PI) were studied by molecular dynamics (MD) simulations, and the effect of SiO₂ surface treated with coupling agent on the mechanical properties of PI was investigated by experiment. At the same doping volume fraction (5%), the simulation results show that the surface interaction energy between the matrix and particle gradually increases with the radius of the embedded nanoparticles. Meanwhile, the interface interaction energy and mechanical properties of the sphere‐type were significantly higher than the ones of other shaped nanoparticles. Moreover, the simulations were compared with the experimental results; atomic force microscopy and scanning electron microscopy images can verify that after being treated with coupling agent, interface interaction between nanosilica and PI enhances quite a little. The mechanical experimental results show that the tensile strength and elasticity modulus of pure PI, unbonded (UB) PI/SiO₂, and bonded PI/SiO₂ films are 34.47 and 1.13, 36.46 and 1.32, and 66.20 MPa and 1.72 GPa, respectively. It is indicated that the coupling agent plays a crucial role in nanocomposites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48595.

中文翻译：

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不同界面结构的纳米二氧化硅对聚酰亚胺/ SiO2复合材料力学性能的影响

在本文中，通过分子动力学（MD）模拟研究了偶联剂，二氧化硅粒径和颗粒形状对聚酰亚胺（PI）力学性能的影响，以及SiO ₂的影响实验研究了偶联剂处理表面对PI的力学性能的影响。在相同的掺杂体积分数（5％）下，仿真结果表明，基体与颗粒之间的表面相互作用能随着嵌入纳米颗粒的半径而逐渐增加。同时，球形类型的界面相互作用能和机械性能显着高于其他形状的纳米颗粒。此外，将仿真结果与实验结果进行了比较。原子力显微镜和扫描电子显微镜图像可以验证，在用偶联剂处理后，纳米二氧化硅和PI之间的界面相互作用增强了很多。力学实验结果表明，纯PI，未粘结（UB）PI / SiO的拉伸强度和弹性模量_{如图2所示}，粘合的PI / SiO ₂膜分别为34.47和1.13、36.46和1.32、66.20 MPa和1.72 GPa。结果表明，偶联剂在纳米复合材料中起着至关重要的作用。分级为4 +©2019 Wiley Periodicals，Inc.J.Appl。Polym。科学 2020，137，48595。