Development of electroactive nanocomposites based on poly(vinylidene fluoride-hexafluoropropylene)/polycarbonate blends with improved dielectric, thermal, and mechanical properties

Poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)), as one of the best known piezoelectric polymers, offers unique properties which makes it material of choice for many cutting-edge technologies such as sensors, actuators, and generators. However, the dielectric constant of the polymer in the pure form does not meet the requirements of most practical applications. In this regard, a combination of barium titanate (BT) and carbon nanotube (CNT) nanoparticles are used to boost the dielectric properties of P(VDF-HFP), while blending P(VDF-HFP) with polycarbonate (PC) allows for selective localization and higher dispersion quality of the nanofillers. The incorporation of the nanofillers improves the dielectric properties with a synergistic effect in the quaternary P(VDF-HFP)/PC/BT/CNT 90/10/1.5/1.5 blend nanocomposite while the dielectric loss remains at a remarkably low value. As expected, barium titanate and carbon nanotubes also boost the piezoresponse behavior of the nanocomposites with a repeatable signal as they are exposed to cyclic pressure load. Besides the dielectric and piezoelectric properties, the thermomechanical properties are also promising which are attributed to the high dispersion quality of the nanoparticles and the interaction of polymer chains and the nanofillers at the interface. These novel electroactive nanocomposites have the potential to be used as piezoelectric pressure sensors.