Ferroelectric Relaxor Terpolymers: Properties and Potential Applications

Ferroelectric materials are intrinsically multifunctional and have found a broad range of applications. A new class of semicrystalline terpolymers comprising vinylidene fluoride (VDF), trifluoroethylene (TrFE), and 1,1-chlorofluoroethylene (CFE), were prepared at the Institut Franco-Allem and de Recherches in Saint-Louis (ISL) via a suspension polymerization process. Relevant studies and results show that this class of electroactive polymers offers unique properties in comparison with other ferroelectric polymers. The terpolymer exhibits high electrostrictive strain (≫7%) with relatively high modulus (≫0.3GPa). It has been also observed that the large electrostrictive strain is nearly constant in the temperature range from 20 °C to 80 °C. These terpolymers are strong candidates for new devices. Example of the motion and of the performance of terpolymer in a unimorph configuration is presented._The high room temperature relative dielectric constant ( 50), which is the highest among all the known polymers), high induced polarization (0.05 C/m²), and high electric breakdown field (≫400 MV/m) lead to very high volume efficiency for the electric energy storage operated under high voltage (10 J/cm³).