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Structure and dielectric breakdown strength of nano calcium carbonate/polypropylene composites
Author(s) -
Virtanen Suvi,
Ranta Hannes,
Ahonen Susanna,
Karttunen Mikko,
Pelto Jani,
Kannus Kari,
Pettersson Mika
Publication year - 2014
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.39504
Subject(s) - materials science , composite material , dielectric , polypropylene , calcium carbonate , dispersion (optics) , raman spectroscopy , nanoparticle , transmission electron microscopy , nano , dielectric strength , doping , epoxy , permittivity , scanning electron microscope , filler (materials) , nanotechnology , optics , optoelectronics , physics
Nanodielectrics, a 21st‐century phenomena, is envisioned to be the answer for material challenges in progressive high‐voltage technology. It is well known that the proper dispersion of nanoparticles plays a key role in improving the dielectric properties of a material, but to understand where changes in the properties of a material originate, it is also essential to reveal the multiscale structure of the material. In this study, the dielectric permittivity, breakdown strength, and structure of nano calcium carbonate (nano‐CaCO 3 )/polypropylene composites with 1.8–8.1 wt % doping were characterized systematically. The combined results from transmission electron microscopy, Raman microscopy, and optical microscopy show that the quality of nanodispersion was similar in all of the filler concentrations studied. However, all of the samples also contained smoothly distributed microparticles. The density of the microparticles increased exponentially when the concentration of nano‐CaCO 3 was increased in the manufacturing process. The dielectric direct‐current breakdown of the composites had a maximum at 1.8 wt % concentration and then decreased as the filler concentration was increased. The differences could be explained by the existence of large microparticles rather than the quality of the nanoparticle dispersion; this indicated the importance of multiscale characterization. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 39504.