Wan Bangwei, Yang Yang, Guo Rongxin, Fan Zhengming, Deng Peng, Zhang Shibo
Yunnan Key Laboratory of Disaster Reduction in Civil Engineering, Kunming 650500, China.
Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China.
Polymers (Basel). 2023 Mar 12;15(6):1412. doi: 10.3390/polym15061412.
In order to realize effective monitoring for the working performance of seismic isolation structures, a multi-walled carbon nanotube (MWCNT)/methyl vinyl silicone rubber (VMQ) composite was prepared via mechanical blending using dicumyl peroxide (DCP) and 2,5-dimethyl-2,5-di(tert-butyl peroxy)hexane (DBPMH) as vulcanizing agents. The effects of the different vulcanizing agents on the dispersion of the MWCNT, electrical conductivity, mechanical properties, and resistance-strain response of the composites were investigated. The experimental results showed that the percolation threshold of the composites prepared with the two vulcanizing agents was low, while the DCP-vulcanized composites showed high mechanical properties and a better resistance-strain response sensitivity and stability, especially after 15,000 loading cycles. According to the analysis using scanning electron microscopy and Fourier infrared spectroscopy, it was found that the DCP contributed higher vulcanization activity, a denser cross-linking network, better and uniform dispersion, and a more stable damage-reconstruction mechanism for the MWCNT network during the deformation load. Thus, the DCP-vulcanized composites showed better mechanical performance and electrical response abilities. When employing an analytical model based on the tunnel effect theory, the mechanism of the resistance-strain response was explained, and the potential of this composite for real-time strain monitoring for large deformation structures was confirmed.
为实现对隔震结构工作性能的有效监测，以过氧化二异丙苯（DCP）和2,5-二甲基-2,5-二叔丁基过氧己烷（DBPMH）作为硫化剂，通过机械共混制备了多壁碳纳米管（MWCNT）/甲基乙烯基硅橡胶（VMQ）复合材料。研究了不同硫化剂对复合材料中MWCNT的分散性、电导率、力学性能以及电阻-应变响应的影响。实验结果表明，采用这两种硫化剂制备的复合材料的渗流阈值较低，而DCP硫化的复合材料具有较高的力学性能以及更好的电阻-应变响应灵敏度和稳定性，尤其是在15000次加载循环后。通过扫描电子显微镜和傅里叶红外光谱分析发现，DCP具有更高的硫化活性、更致密的交联网络、更好且均匀的分散性，并且在变形载荷作用下MWCNT网络具有更稳定的损伤-重建机制。因此，DCP硫化的复合材料表现出更好的力学性能和电响应能力。当采用基于隧道效应理论的分析模型时，解释了电阻-应变响应的机理，并证实了该复合材料用于大型变形结构实时应变监测的潜力。
