TY  - JOUR
A1  - Raman Venkatesan, Thulasinath
A1  - Wübbenhorst, Michael
A1  - Gerhard, Reimund
T1  - Structure-property relationships in three-phase relaxor-ferroelectric terpolymers
JF  - Ferroelectrics
N2  - Poly(vinylidenefluoride-trifluoroethylene)-based (P(VDF-TrFE)-based) terpolymers represent a new class of electroactive polymer materials that are relaxor-ferroelectric (RF) polymers and that offer unique and attractive property combinations in comparison with conventional ferroelectric polymers. The RF state is achieved by introducing a fluorine-containing termonomer as a "defect" into the ferroelectric P(VDF-TrFE) copolymer, which reduces the interaction between the VDF/TrFE dipoles. The resulting terpolymer exhibits a low Curie transition temperature and small remanent and coercive fields yielding a slim hysteresis loop that is typical for RF materials. Though the macroscopic behavior is similar to RF ceramics, the mechanisms of relaxor ferroelectricity in semi-crystalline polymers are different and not fully understood yet. Structure-property relationships play an important role in RF terpolymers, as they govern the final RF properties. Hence, a review of important characteristics, previous studies and relevant developments of P(VDF-TrFE)-based terfluoropolymers with either chlorofluoroethylene (CFE) or chlorotrifluoroethylene (CTFE) as the termonomer is deemed useful. The role of the termonomer and of its composition, as well as the effects of the processing conditions on the semi-crystalline structure which in turn affects the final RF properties are discussed in detail. In addition, the presence of noteworthy transition(s) in the mid-temperature range and the influence of preparation conditions on those transitions are reviewed. A better understanding of the fundamental aspects affecting the semi-crystalline structures will help to elucidate the nature of RF activity in VDF-based terpolymers and also help to further improve their applications-relevant electroactive properties.
KW  - Relaxor-ferroelectric (RF) fluoropolymers
KW  - structure-property
KW  - relationships
KW  - Curie transition
KW  - dielectric hysteresis
KW  - thermal
KW  - processing
KW  - mid-temperature transition(s)
Y1  - 2022
U6  - https://doi.org/10.1080/00150193.2021.2014260
SN  - 0015-0193
SN  - 1563-5112
VL  - 586
IS  - 1
SP  - 60
EP  - 81
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  -