The Research Of Effect Of Poly(Vinyl Phenol) On Crystallization Behavior And Ferroelectric Performance Of Poly(Vinylidene Fluride-Trifluroethylene)

Among polymer ferroelectric materials, P(VDF-TrFE) is widely used ferroelectric polymer memories with its excellent processability, excellent chemical stability and a high spontaneous polarization. However, its high surface roughness, high leakage and low thermal stability, which limit the commercial applications of P(VDF-TrFE). In this paper, a small amount of a low dielectric constant polymer PVPh was added to the P(VDF-TrFE) obtained P(VDF-TrFE)/PVPh blends, we will study the effect of PVPh on P(VDF-TrFE) from two perspectives including crystallization behavior and electrical properties.1. We prepared a stable phase separation structure of the P(VDF-TrFE)/PVPh blend film, the accession of the PVPh leaded to the grain size of P(VDF-TrFE) and the roughness of the P(VDF-TrFE)/PVPh blend film decrease. The PVPh with spherical morphology distributed in blends. With the increase of the content of the PVPh, the size of PVPh increased. The addition of PVPh improved the thermal stability of P(VDF-TrFE). A small amount of PVPh (when the concentration of PVPh was 5% or less) did not affect the Curie phase transition temperature of P(VDF-TrFE); a further increase of the content of PVPh (when the concentration of PVPh increased to 10%), will reduce the Curie transition temperature of P(VDF-TrFE).2. The results of PFM show that the polarized b-axis of the ferroelectric crystal orientated perpendicular to the substrate, and the method of the cold crystallization treatment enabled the sample having the best ferroelectric properties. The accession of the PVPh leaded to the the coercive field voltage of the blend films increase a little. The test result of the blends capacitor devices with structure of Sandwich exhibited that excellent the accession of the PVPh leaded to the remnant polarization of P(VDF-TrFE) decrease, but it also leaded the leakage current density of devices decrese significantly.The test result of the dielectric spectrometer exhibited that PVPh also helped reduce the dielectric loss of the blend film. Through the method of blending modification, the ferroelectric materials with integrated performance was obtained.