有机化纳米SiO2填充尼龙66复合物的结构与性能

通过原位表面修饰法制备了有机化纳米SiO2,用熔融共混法制备了尼龙66/SiO2纳米微粒复合材料并研究了复合材料的力学性能.通过示差扫描量热分析(DSC)和动态力学热分析(DMA)研究了复合材料的结晶性能和动态热机械性能.研究表明,纳米SiO2质量分数为4%的复合材料性能提高较为明显,其中简支梁缺口冲击强度提高51.3%,断裂伸长率提高47.3%,弹性模量提高23.8%;纳米SiO2在尼龙66结晶过程中起到异相成核作用,限制了尼龙66的分子链段运动使得复合材料的玻璃化转变温度提高,提高了尼龙66的结晶速率,降低了结晶度;纳米SiO2质量分数为1%复合材料在0℃时的储能模量较纯尼龙66提高21.1%,损耗模量较纯尼龙66提高83.6%,说明纳米SiO2能改善复合材料的低温脆性.

Structure and Mechanical Properties of Nylon 66/Organo- Silica Nanocomposites

Nano-SiO_2 was prepared by situ surface-modification.Nylon 66/nano-SiO_2 composites with different content of nano-SiO_2 were prepared with melt blending method and their mechanical properties were investigated.The crystallization properties and the dynamic thermo-mechanical properties were studied by differential scanning calorimetry(DSC) and dynamic mechanical analysis(DMA).The results show that the properties of composite material(mass fraction of SiO_2 is 4%) are improved obviously,the impact strength breakage elongation and elastic modulus of the composites are improved by 51.3%,47.3% and 23.8%,respectively.The crystallization rate of nanocomposites is increased and the nano-SiO_2 works as a nucleation agent and decreases the crystallinity of nanocomposites,the glass-transition temperatures of the nanocomposites are higher than that of the net nylon 66.When the mass fraction of SiO_2 is 1%,the storage modulus and loss modulus of nanocomposites are improved by 21.1% and 83.6% respectively compared with net nylon 66,which means that the nano-SiO_2 can improve the low temperature brittleness.