新型硅橡胶基压阻敏感复合材料制备及其性能研究

Preparation and properties of novel silicone-rubber-matrix piezoresistive sensitive composites

以多壁碳纳米管(MWNT)和纳米二氧化硅作为助填料,采用三辊研磨机制备了(MWNT-SiO2)/RTV复合材料,研究其压阻和介电性能。结果表明,纳米SiO2经KH570改性,其在基体中分散性及界面结合提高;(MWNT-SiO2)/RTV复合材料压力敏感性增强,当外界压力为150N时,含5%二氧化硅的复合材料相对电阻是MWNT/RTV复合材料的近2倍,其压力敏感性提高近1倍,其电阻与压力呈良好的线性关系。随着碳纳米管长径比的增大(MWNT-SiO2)/RTV复合材料压力敏感性变弱。(MWNT-SiO2)/RTV复合材料介电常数随频率的增加而减少,随SiO2含量的增加而增加。

By employing multi-walled carbon nanotubes（MWNT） and SiO2 as fillers and silicone as matrix,（MWNT-SiO2）/RTV composites were prepared by three roll mills mixing method and the piezoresistive and dielectric properties of composites were investigated.The results showed that the use of KH570 modified silica could improve the dispersion of fillers in matrix and the interface binding between fillers and RTV.After modified SiO2,the pressure sensitivity of（MWNT-SiO2）/RTV composite become stronger.When the outside pressure is 150N,the relative resistance of the（MWNT-SiO2）/RTV composite with 5% SiO2 is nearly twice as much or as that of the MWNT/RTV composite and the piezoresistive sensitivity should increase nearly double.In addition,the resistance and pressure showed a good linear relationship.With increasing the aspect ratio of MWNT,the piezoresistive sensitivity of（MWNT-SiO2）/RTV composites is weaker.Dielectric constant of（MWNT-SiO2）/RTV composites decreases with increasing frequency and it increases with the increase of silica content.