CB/TPU复合材料的制备及其导电性能研究

Preparationand conductive properties of CB/TPU composites

通过激光选区烧结技术对机械混合获得CB/TPU复合粉末进行烧结,制备了柔性导电复合材料,研究了不同CB/TPU质量比对导电性、压阻特性、迟滞性、弛豫性和重复性的影响。结果表明,CB可显著改善复合材料的导电性,根据CB/TPU质量比的不同,复合材料的电导率在7.69×10-4至2.5×10-1S/m之间,CB填充TPU基体的渗流阈值约为2.9wt%。压阻特性测试结果表明,阻值倒数与压力值成正比,1/R-F曲线斜率随着CB/TPU质量比增大而增大。随着CB/TPU质量比的增大,试样的迟滞性下降,但是弛豫性增强。经过1000次20N加载-卸载循环后,其仍能保持明显的压阻性能,但是电阻值有所下降,且下降的幅度随CB/TPU质量比的增大而增大。

CB/TPU composite powders obtained by mechanical mixing were sintered by selective laser sintering,and flexible conductive composites were prepared.The influence of different CB/TPU mass ratios on the electrical conductivity,piezoresistive property,hysteresis property,relaxivity property and reproducibility of the materials were investigated.The results showed that the CB can significantly improve the conductivity of the composite.The electrical conductivity of composites varied from 7.69×10-4 to 2.5×10-1S/m,depending on the mass ratio of CB/TPU.The percolation threshold of the CB filled TPU is about 2.9 wt%.The piezoresistive tests showed that the reciprocal of the resistance was proportional to the pressure,and the slope of the 1/R-F curve increased as the mass ratio of CB/TPU increased.With the increase of CB/TPU mass ratio,the hysteresis property of the composites was weakened,whereas the relaxivity property was enhanced.After 1000 loading-unloading cyclic tests at 20 N,remarkable piezoresistive property remained,However,the resistance decreased,and the magnitude of the decrease enlarged as the mass ratio of CB/TPU increased.