The particle size effect of rice husk on thermal conductivity and dielectric constant of RTV Silicon rice husk composites

Abstract

The rice husk (RH) is a wide agricultural resource by-product of rice milling process in Iraq. In this work, RH is used as filler to modified thermal conductivity and dielectric constant of RTV silicone. RH-RTV silicone composites are prepared with different RH filler particle sizes, they are equal to 6.5mm (raw RH), 1.18mm, 250 μm, 125 μm, 75 μm, and 50μm. The levels of RH filler loading (1, 3, 5, 7, 10, 15 and 20) (wt %). The thermal conductivity and dielectric constant of all RH-RTV silicone composites are studied. The effect of varying frequency (from 500 Hz to 1 MHz) on dielectric constant all composites is studied. The thermal conductivity of RH-RTV silicone composites decrease with RH filler concentration increases and particle size decreases, thermal conductivity has minimum value at 20%wt. The particle size effect on thermal conductivity of composite is very observably at 50μm particle. The dielectric constant of RH-RTV silicone composites is increased when RH filler concentration increases and particle size decreases, thy have maximum value at 20%wt and 50μm RH particle. The varying of frequency is low effect on 50μm RH-RTV silicone composites.