Novel flexible P(VDF-CTFE)/PA11-g-GMA ferroelectric polymer films with high energy density

were prepared via melt extrusion in a twin screw extruder and thermal stretching.The preparation protocol including two steps:(1) as an interface compatilizer

GMA was introduced into nylon11 (PA11) for preparing blended films; (2) based on stretch processing

the s-P(VDF-CTFE)/PA11-g-GMA films were obtained.The crystal configuration and micromorphology of the films were characterized by x-ray powder diffraction (XRD) and scanning electron microscopy (SEM).The electric energy storage and discharge behaviors in the films were studied by electric displacement (D)-electric field (E) loop measurements.It was found that the interface cohesive ability between P(VDF-CTFE) and PA11 was improved because of the strong polar effect of GMA

which is responsible for the increasing of the dipoles and high polarization under the applied fields

clearly observed in the dielectric spectra of the copolymer films.It is also demonstrated that PVDF segments in uniaxially stretched P(VDF-CTFE)/PA11-g-GMA films form large amount of -crystal.That is to say

if the crystalline morphology with a high -crystal content can be further modified to help the discharge process

a polymer capacitor film with high energy densities and low dielectric loss can be achieved.In this paper

the breakdown strength and energy density of the flexible s-P(VDF-CTFE)/PA11-g-GMA films are 275 MV/m and 8.09 J/cm3

respectively.It shows a great potential of a new class of polymer films with high energy density for flexible capacitors.