Review on the properties of the ferrorelaxor polymers and some new recent developments

Abstract

It has been found that by introducing defects into the P(VDF-TrFE) copolymers, it is possible to convert the polymer from a normal ferroelectric to a relaxor ferroelectric. A new class of ferroelectric polymers, i.e., the terpolymers of P(VDF-TrFE-CFE) or of P(VDF-TrFE-CTFE), was developed from the normal ferroelectric PVDF-TrFE polymer by employing proper defect modifications which eliminate detrimental effects associated with a normal first order F-P transition while maintaining high material responses. Relevant studies show that this class of electroactive polymers offers unique properties in comparison with other ferroelectric polymers. The syntheses of these relaxor ferroelectric polymers have been done by a combination of the suspension polymerization process and an oxygen-activated initiator at a temperature of 40°C. Films from cast solution can be made in different lengths and thicknesses. Stretching of these films increases the performance as well as the mechanical properties. These relaxor-ferroelectric terpolymers P(VDF-TrFE-CFE), P(VDF-TrFE-CTFE) are multifunctional, i.e., electrostrictive material, dielectric for electric energy storage. The terpolymer exhibits high electrostrictive strain (>7%) with relatively high modulus (>0.4 GPa). Examples of devices applications using unimorphe systems are presented. Micropump and Optical device concerning a liquid-filled varifocal lens on a chip are described.Dedicated to Professor Reimund Gerhard.F. Bauer ( ) Piézotech S.A.S., 9, rue de Colmar,

Fully printed flexible audio system on the basis of low‐voltage polymeric organic field effect transistors with three layer dielectric

“…A continuation of this approach was made by the introduction of ter‐polymers consisting of a third monomer added to conventional copolymers like P(VDF‐TrFE). This leads to so called relaxor ferroelectricity with strongly reduced hysteresis and very high room temperature relative permittivity of 42–77 at a frequency of 1 kHz in the case of poly[(vinylidenefluoride‐ co ‐trifluoroethylen‐chlorotrifluoroethylen] (P(VDF‐TrFE‐CTFE)) …”

“…This leads to so called relaxor ferroelectricity with strongly reduced hysteresis and very high room temperature relative permittivity of 42-77 at a frequency of 1 kHz in the case of poly[(vinylidenefluoride-co-trifluoroethylen-chlorotrifluoroethylen] (P(VDF-TrFE-CTFE)). [26][27][28][29][30] Because of these promising properties, P(VDF-TrFE-CTFE) was selected for this work to serve as the high-k dielectric in a vertical stack combination with the low-k dielectric CYTOP to produce fully printed OFETs. However, as CYTOP provides an ultranonpolar surface with very low surface energy, a novel polymeric intermediate layer was developed for perfect layer compatibility.…”

High breakdown strength and low loss binary polymer blends of poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene) and poly(methyl methacrylate)

“…The bulky comonomer of CFE that is incorporated into the P(VDF‐TrFE) chain enlarges the interchain distance and introduces random defects to the terpolymer, which will reduce the crystal lattice positional ordering and ferroelectric domain size. The random defect introduction broadens the ferroelectric transition and reduces the ferroelectric‐paraelectric (F‐P) transition temperature, moving the Curie transition to near ambient temperature . As a result, the dielectric constant is greatly improved.…”

“…All data were analyzed using Jade to near ambient temperature. [19][20][21] As a result, the dielectric constant is greatly improved. Increasing the amount of PMMA results in a much decreased dielectric constant.…”

Temperature dependence of flexoelectric response in ferroelectric and relaxor polymer thin films

“…The dielectric constant in relaxors yields broad peaks as a function of temperature that is also frequency dependent. 30,31 …”