Lead-free elastomer nanocomposite with piezoelectric properties

Piezoelectric elastomer composites are a subgroup of piezoelectric polymers. They can undergo large deformation, making them an important research topic for piezoelectric materials. Nowadays, the use of lead is decreasing due to its toxic effects on human health and the environment, which increases the importance of lead-free piezoelectric materials. In this study, both piezoelectricity of lead-free type 2 FKM rubber and the effects of vulcanization and polarization processes on its piezoelectricity have been studied. Piezoelectricity of the samples has been determined by measuring the open-circuit voltage of samples under dynamic load. It has been found that the vulcanization decreases the piezoelectric properties of the elastomer compound, but both vulcanized and unvulcanized samples can be polarized under proper conditions to increase piezoelectric properties. The maximum measured open-circuit voltage is 27 V for unvulcanized FKM, whereas it is 20 V for vulcanized FKM. The effect of polarization on the crosslinking density of vulcanized and unvulcanized rubber is also studied, but a significant relationship could not be found between crosslinking density of the samples and the applied electric field. However, if polarization takes place under high temperatures and under compression, crosslinking occurs. The prepared FKM rubber in the study can be used in some piezoelectric applications where elastic properties are required.