Multicaloric Effects in P(VDF-TrFe-CTFE) Terpolymers

PVDF-based polymers are outstanding organic electrocaloric polymers [1-3]. Their combination of electroactivity, piezoelectricity, malleability, low cost, and chemical tunability makes them highly attractive for caloric applications [4].
In particular, P(VDF-TrFE-CTFE) exhibits a relaxor-ferroelectric behaviour [5-6]. This polymer consists of small alpha-phase crystals and an amorphous component [7]. At room temperature, it shows a pronounced electrocaloric effect [8]. When stretched 12 times its initial length, P(VDF-TrFE-CTFE) displays an elastic regime that underpins its elastocaloric properties [9], while also retaining its electrocaloric counterpart.
The thin film geometry of this material allows excellent conditions for applying electric and uniaxial stress at the same time. We have studied the synergic potential of combined electric and mechanical stress, directly characterising the multicaloric effects in P(VDF-TrFE-CTFE) terpolymers using thermometry data along the entire stress-strain curve and at temperatures near room temperature. Our study seeks to enhance the understanding of the physical causes behind the caloric effects in the terpolymer, paving the way for further exploration and enhancement of multicaloric systems.

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