Development and characterization of a novolac resin/BaTiO₃ nanoparticles composite system

Abstract

Polymer composites incorporating ferroelectric and piezoelectric crystal particles, randomly distributed within the host matrix, represent a novel class of materials. In this study, composite materials consisted of novolac resin and barium titanate nanoparticles were prepared and examined, varying the nanofiller content. Structural characterization was conducted via X-ray diffraction and scanning electron microscopy. Mechanical and dielectric properties were examined by employing bending and shear strength tests and broadband dielectric spectroscopy, respectively. Bending and shear strength found to decrease with the filler content. Dielectric permittivity was found to increase significantly with filler content, and the detected relaxation processes were attributed to interfacial polarization, glass to rubber transition of the matrix, and reorientation of polar side groups of the polymer chain. Although, the mechanical performance of the examined systems seems not to be attractive in applications due to its brittleness, nanocomposites' dielectric response could be proved interesting in electrical and electronic devices applications.

Barium titanate/polyester resin nanocomposites: Development, structure-properties relationship and energy storage capability

“…Up to now, the most important utility of BaTiO 3 / polymer composites is based on their dielectric properties, because of barium titanate's high dielectric permittivity value (high-K material) [12]. Nevertheless serious drawback for this kind of composites is their poor mechanical properties [13]. The latter is related to the brittle nature of the ceramic filler, and to the possibility that distributed ceramic particles could act as stress raisers.…”

Design and Construction of Capacitors with the Use of Nano-Barium Titanate’s (BaTiO3) Composite Materials

“…The composite materials that were used as dielectric materials in the construction of capacitors are as follows: Novolac with 10% ΒaΤiO 3 w/w, unsaturated polyesters with 10% BaTiO 3 w/w, and commercial epoxy resin (CER) with 10% BaTiO 3 w/w [2]. 3 10% w/w.…”

“…While the molded mold has four lead caps, whose role is to seal-seal the mold so that no liquid material escapes before it is completely cured. The die molds (open or closed type) are placed inside the thermopress, which follows a particular curing program, depending on the type of polymer matrix [2,3]. The molar ratio of each major raw material is shown in Table 1.…”

“…Except the composite material Novolac-BT, the mechanical pressure, which was exerted each time in the composite materials, was the maximum from the PVC screws. This composite material is characterized with a porous structure and it has poor mechanical properties [6,7]. Figure 6, the unsaturated polyester M 1 A 3 PA 6 -BT is distinguished with the highest capacitance, in the range of frequency 10 kHz up to 1 MHz.…”

“…We observe that, for = 100 kHz, the capacitor with the dielectric-composite material M 1 A 3 PA 6 -BT has the largest capacity ( ) and electric conductivity ( ) while the composite material with the dielectric NV-BT has got the smallest capacitance ( ) and electric conductivity ( ) (Table 3). This happens because the composite material M 1 A 3 PA 6 -BT has got the bigger quantity of phthalic anhydride [7,11]. …”