Effect of temperature on electrical behavior of flyash‐filled epoxy gradient composites

Abstract

Functionally gradient composites of epoxy resin having different weight percentages of flyash were prepared under centrifugal force to obtain gradient in density, hardness, and electrical properties. Effect of temperature and frequency variation on dielectric constant (Ј), tan ␦, and ac conductivity was determined by using a 4274 A Multi-Frequency LCR meter. Electrical measurements were carried out in a temperature range from 40 to 180°C and in a frequency range from 1 to 100 kHz. It was observed that the dielectric constant and tan ␦ increased with increase in temperature and decreased with increase in frequency. The ac conductivity increases with increase in temperature and frequency. The increased weight percentage of flyash increased the compaction of flyash particle in the flyash-rich phase of graded composites, which would have increased the dielectric constant (Ј), tan ␦, and ac conductivity. Shore D hardness and density of the functionally gradient composites has also been determined and reported. A continuous increase in the hardness from 69 to 76 and density from 1.287 to 1.41 g/cc has been observed.

Morphology, thermal and mechanical properties of the polyhedral oligomeric silsesquioxane side‐chain epoxy hybrid material

“…When the IPEP contents were lower than 50 wt %, the hardness increased with the IPEP contents. As the inorganic silica segments (POSS) increased and covalent bonds of the inorganic POSS segments formed across the interface between the inorganic segments and organic segments 47–48. Liu et al49 indicated that introduction of the inorganic segments into the polymer materials could improve the wear resistance and surface hardness of the nanocomposites.…”

Thermal and rheological behavior of ultrafine fly ash filled LDPE composites

“…Fly ash has also been used in the development of functionally graded polymer composites to obtain gradient in density, hardness and electrical properties. 6 It has been advocated that fly ash can be used as filler or the supporting filler in the polymers. 7 The fine fly ash particles improve dielectric properties, rigidity and heat deflection temperature of polymers.…”

“…In addition to several commercial fillers such as silica, calcium carbonate, talc, carbon black, rutile, etc., the fly ash has been incorporated in polymers to improve mechanical, thermal, and electrical properties. Fly ash has also been used in the development of functionally graded polymer composites to obtain gradient in density, hardness and electrical properties 6. It has been advocated that fly ash can be used as filler or the supporting filler in the polymers 7.…”

“…Many technical papers are available in the literature1–10 related to the material characteristics in solid state but the behavior of fly ash filled polymers in molten state is rarely reported 6, 10. The properties of a composite in melt‐form depend upon the shear history of melt.…”

Deformation and fracture behavior of treated f ly ash-f illed polycarbonate-toughened epoxy resin composites

“…Bose and Mahanwar 5 observed that the addition of fly ash to nylon 6 improved its rigidity, heat resistance, and dimensional stability. Chand et al 6,7 developed a new type of cheaper fly ash-filled PP/polymethyl methacrylate blend system and also studied the effect of temperature on electrical behavior of fly ash-filled epoxy gradient composites. Kishore et al [8][9][10][11] investigated the compressive properties of epoxy and hybrid epoxy composites filled with fly ash under different conditions.…”