导电炭黑/硅橡胶复合材料的电阻-应变响应特性

Resistance⁃Strain Response Characterization of Conductive Carbon Black/Silicone Rubber Composites

导电聚合物复合材料(CPCs)在隔震支座的应变监测具有广阔的应用前景。本工作采用机械共混法制备了导电炭黑(CB)/甲基乙烯基硅橡胶(VMQ)复合材料,通过场发扫描电镜(SEM)分析,发现适量的CB能够均匀分散在VMQ中,形成三维隧穿导电网络,复合材料的渗流阈值为7.51wt%,传感范围大于150%,灵敏度GF大于2.87,在不同应变下多次循环中具有稳定的电阻-应变响应信号,特别是在5 000次循环中展现出优异的电阻信号稳定性,同时克服了电阻-应变响应信号中的肩峰现象。通过隧道效应理论模型分析,解释了复合材料的电阻-应变响应机理。该复合材料具有对大变形下隔震支座的应变监测的潜力。

Conductive polymer composites(CPCs)have a wide range of applications for strain monitoring of seismic isolation bearings.Conductive carbon black(CB)/methyl vinyl silicone rubber(VMQ)composites were prepared by mechanical blending.Through field emission scanning electron microscopy(SEM)analysis,it is found that an appropriate amount of CB can be uniformly dispersed in VMQ,forming a three⁃dimensional tunneling conductive network.The percolation threshold of the composites is 7.51wt%,the sensing range is greater than 150%,and the sensitivity is 2.87,It exhibits stable resistance strain response signals in multiple cycles under different strains,especially in 5000 cycles,demonstrating excellent resistance signal stability while overcoming the shoulder peak phenomenon in resistance strain response signals.By analyzing the tunnel effect theory model,the resistance strain response mechanism was explained,The composite has potential for strain monitoring of seismic isolation bearings under large deformations.