【摘要】 以常见的3种硅烷偶联剂KH550、KH560和KH570作为改性剂,对纳米SiO₂进行改性处理。将3种改性纳米SiO₂分别制备出纳米SiO₂/环氧树脂复合材料。对改性纳米粒子进行红外测试表征,使用动态光散射法对粒径进行表征;对于所制得的复合材料在常温环境下进行冲击强度表征以及低温环境下进行热膨胀系数表征。结果表明:3种偶联剂改性后的SiO₂的平均粒径在（200±50）nm范围之内,多分布系数（PDI）在0.30±0.05范围内,不同偶联剂改性对于复合材料冲击强度的影响差异较小,相差不超过7.37%;而对复合材料热膨胀系数（CTE）的影响有差异较大。其中SiO₂含量为9%时,且在–183℃时,偶联剂KH560对于SiO₂/环氧树脂复合材料体系的热膨胀系数性能改善效果最好,同等条件下KH550和KH570改性复合材料的热膨胀系数则分别提高了大约1.19%和23.7%。更多还原

【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.更多还原