Ferroelectric Relaxor Terpolymers: Properties and Potential Applications

Ferroelectric materials are intrinsically multifunctional and have found a broad range of applications. A new class of semicrystaltine terpolymers comprising vinylidene fluoride (VDF), trifluoroethylene (TrFE), and 1,1-chlorofluoroethylene (CFE), were prepared at the Institut Franco-Allemand 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 degrees C T to 80 degrees 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 (similar to 0.05 C/m(2)), and high electric breakdown field (>400 MV/m) lead to very high volume efficiency for the electric energy storage operated under high voltage (similar to 10 j/cm(3)).