The effect of processing conditions on the morphology, thermomechanical, dielectric, and piezoelectric properties of P(VDF-TrFE)/BaTiO3 composites

Abstract

In this study (0-3) P(VDF-TrFE)/BaTiO 3 composites containing up to 60 vol% of ceramic phase were prepared by solvent casting or compression molding. Their thermomechanical, dielectric, and piezoelectric properties were investigated, and discussed in the light of the properties of the basic components, the processing route and the resulting morphology. The crystalline structure of the P(VDF-TrFE) matrix was found to be highly dependent on the processing route, while the structure of BaTiO 3 was not affected by any of the processing steps. The mechanical properties of the solvent cast materials showed a maximum at 30 vol% BaTiO 3 , while they increased monotonically with BaTiO 3 content for compression molded materials. This difference was attributed to a higher amount of porosity and inhomogeneities in the solvent cast composites. Permittivity as high as 120 and piezoelectric coefficient d 33 up to 32 pC/N were obtained for compression molded composites, and the observed decrease in d 33 with aging time was attributed to the effect of mechanical stress release in the polymer matrix.

Effect of silane coupling agent on the morphology, structure, and properties of poly(vinylidene fluoride–trifluoroethylene)/BaTiO3 composites

“…The second one (BT2) was an in-house made BaTiO 3 powder (0.7 µm), obtained by milling BaCO 3 and TiO 2 powders in stoichiometric ratio, and performing calcination at 1100 °C for 3 hours followed by further milling. The characterization of the BT1 and BT2 powders was reported in detail previously [17]. The third powder (BT3) was BaTiO 3 99.95%, electronic grade, average particle size 0.2 µm from Inframat Advanced Materials LLC (Manchester, CT, USA).…”

“…While most of the research on VDF based polymer composites historically focused on their dielectric and electromechanical properties, recently more attention has also been dedicated to the understanding of their processing and their morphological, structural, 4 thermal and mechanical properties [16][17][18][19][20][21][22][23]. The fabrication of VDF polymer based composites poses challenges due to the difficulty of homogeneously dispersing the inorganic filler into the fluoropolymer matrix and to the poor matrix-filler adhesion.…”

“…Furthermore, in several instances fairly high volume fractions of filler (above 50 %) are needed in order to obtain the desired dielectric and electromechanical properties, and particularly when solvent based fabrication routes are used, porosity plays an important role [17].…”

“…The Curie temperatures (T C ) and melting temperatures (T m ) of all tested materials are summarized in Table 1. The structural differences between SC and CM composites arising from the different fabrication processes, which are reflected in the DSC thermograms, were discussed in detail in a previous paper [17] and will not be specifically covered here. showed some variability in the shape and position of the endotherm peaks, however with no correlation with the BaTiO 3 surface modification.…”

BaTiO3–P(VDF-TrFE) composite ink properties for printed decoupling capacitors

“…The printed composite showed higher relative permittivity than has been previously reported with the same loading level, while the dielectric losses remain at the same level [8][9][10][11][12][13][14][15]. This is almost certainly due to the selection of the matrix material and the particle size, and the new fabrication technique including chemical solution processing with specific surfactant and printing which enabled a low agglomeration level and a more uniform distribution of the filler.…”