Preparation, microstructure and properties of epoxy-based composites containing carbon nanotubes and PMN-PZT piezoceramics as rigid piezo-damping materials

In present work, we prepared a series of the epoxy-based composite materials containing multi-walled carbon nanotubes (CNTs) and piezoceramic complex of lead magnesium niobate and lead zirconate titanate (PMN-PZT), and their properties were studied. The composites exhibited a percolation threshold in the range of 1–1.5 g CNTs per 100 g epoxy, and under this circumstance, a continuous electro-conductive network was formed. Dynamic mechanical loss factors of the composites were improved when PMN-PZT and CNTs were incorporated at above critical electrical percolation loading, which indicates a good piezo-damping performance. In these composite materials, the PMN-PZT contributes to the transformation of mechanical noise and vibration energies into electric energy, while the CNTs serve in shorting of the generated electric current to the external circuit. Thermal stabilities and mechanical properties were also improved by incorporating these two fillers. A new type of the rigid piezo-damping materials was designed on the basis of the results in this study.