Characterizations of Coefficient of Thermal Expansion and Impact Strength of Modified Nano-SiO2 / Epoxy Resin
HU Bozhao1 , YUAN Yuhuan2 , MA Jiwen1 , WU Zhanjun3 , CHEN Duo2 , SUN Tao3
(1. School of Aeronautics and Astronautics, Dalian University of Technology, Dalian 116024，China; 2. Faculty of Materials Science and Engineering, Dalian University of Technology, Dalian 116024，China; 3. State Key Laboratory of Structural Analysis for Industrial Equipment, School of Aeronautics and Astronautics, Dalian University of Technology, Dalian 116024，China)
Abstract：Three common silane coupling agents KH550, KH560 and KH570 were used as modifiers to modify the nano-silica respectively. The nano-SiO2/epoxy composite materials were prepared from the three modified nano-silicas. The characterizations of the infrared test of the modified nanoparticles and the dynamic light scattering of the particle size have been tested. The characterizations of the impact strength at normal temperature and coefficient of thermal expansion at low temperature of the prepared composite material have been tested. The results showed that the average particle sizes of SiO2 modified with the three coupling agents are in the range of (200±50)nm.The distribution coefficient (PDI) of the modified SiO2 particles in ethanol is within the range of 0.30±0.05. The effect of different coupling agent modifications on the impact strength of composite materials is small, the difference is not more than 7.37%, but it has the great influence on the CTE of the composite materials. When the concentration of SiO2 is 9%, and under –183℃ , KH560 has the best effect on improving CTE of SiO2 / epoxy composite system among the three coupling agents, while under the same conditions, the CTE of the SiO2 / epoxy composite system modified by KH550 and KH570 are higher about 1.19% and 23.7% respectively.
2020, 
