纳米SiO2/尼龙66复合材料的力学性能和热性能

采用熔融共混的方法在双螺杆挤出机上制备出纳米SiO₂/尼龙66复合材料,并对其力学性能和热性能进行了研究。结果表明：复合材料的拉伸强度和弹性模量随纳米SiO₂含量的增加而提高。当SiO₂质量分数为3％时,复合材料的拉伸强度达到最大,增幅为11.2％;当SiO₂质量分数为5％时,弹性模量达到最大, 增幅为30.1％。复合材料的储能模量和玻璃化转变温度较纯尼龙66也有明显提高。差示扫描量热法（DSC）分析显示,纳米SiO₂的加入一方面阻碍了尼龙66的结晶过程,降低了材料的结晶温度;另一方面它又能作为形核剂,增加尼龙66的形核位置,提高形核率。

Mechanical and thermal properties of nano-SiO2/PA66 composites

The PA66-based nano-composites containing nano-SiO2 were prepared in a twin-screw extruder by melt compounding,and the mechanical and thermal properties of the nano-composites were investigated. The results of mechanical testing show that the tensile strength and Young's modulus of the nano-composites are all reinforced with the addition of silica nano-particles. The tensile strength reaches a maximum at 3% mass fraction,which is 11.2% higher than that of the pure PA66. And the Young's modulus reaches a maximum at 5% mass fraction,which is 30.1% higher than that of the pure PA66. The storage modulus and glass transition temperature of the composites obviously increase compared with those of the pure PA66. The differential scanning calorimetry (DSC) indicates that the incorporation of nano-SiO2,on the one hand,can hinder the crystallization process of PA66. On the other hand,it can act as a nucleation agent and increase the nucleation site and nucleation rate of PA66.