A new class of semicrystalline terpolymers comprising vinylidene fluoride (VDF), trifluoroethylene (TrFE), and 1, 1-chlorofluoroethylene (CFE) or Chlorotrifluoro ethylene (CTFE) can be synthesized at Piezotech S.A.S via a suspension polymerization process.
These polymers exhibit large electrostrictive strain (>7%), High dielectric constant (50) and electrocalorific effects.

Ferroelectric polymers that generate mechanical actuation are currently in high demand due to their many desirable properties, such as flexibility, lightweight and high mechanical strength.

This terpolymer P(VDF-TrFE-CFE) was developed by purposefully introducing defects into the P(VDF-TrFE) copolymers. By introducing these defects into the P(VDF-TrFE) copolymers, the polymer can then be converted from a ferroelectric to a relaxor ferroelectric. Adding the proper defect modifications, 1-chlorofluoroethylene (CFE) in the form of chemical monomer, eliminate effects associated with a normal first order ferroelectric-paraelectric transition.

The structural properties of a class of relaxor ferroelectric polymer, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) [P(VDF-TrFE-CFE)] terpolymer were investigated and compared with those of the poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer.

In a collaborative group effort with Dr. François Bauer, and Professor Qiming Zhang of the Electrical Engineering Department and Materials Research Institute at Pennsylvania State University, they have demonstrated the relaxor ferroelectric behavior of the terpolymer of vinilydene fluoride, trifluoroethylene, and chlorofluoroethylene.

This new class of semi-crystalline terpolymer, P(VDF-TrFE-CFE), is synthesized via a suspension polymerization process and offers many unique properties in comparison with other ferroelectric polymers.
When stressed with an electrical field (~150MV/m), the P(VDF-TrFE-CFE) terpolymer exhibits high electrostrictive strain (>7%) with a relative high modulus (>0.3GPa).

Furthermore, high room temperature dielectric constant (~ 50, to our knowledge, this is the highest among the known polymers), high induced polarization (~ 0.1 C/m2), and high electric breakdown field (>400 MV/m) lead to very high electric energy density for the electric energy storage capacitors.

Références. (PDF Documents)

ieee advances in electrostrictive polymers

Relaxor ferroelectric polymers new development

Science 2006