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.

Iraq is home to the Halexylon Salicornicum plant (HS). This study modifies thermal conductivity and dielectric constant of unsaturated polyester resin using HS as filler (UPE). Different HS filler particle sizes, including 6.5 mm (raw HS), 1.18mm, 250 m, 125 m, 75 m, and 50 m, are used to create HS- UPE composites. HS filler loading levels (1, 3, 5, 7, 10, 15, 20 and 25) (wt percent). All HS- UPE composites' thermal conductivity and dielectric constant are investigated. Study is done on how changes in frequency (from 500 Hz to 1 MHz) affect the dielectric constant of all composites. The thermal conductivity of HS- UPE composites falls as the concentration of HS filler increases and particle size reduces; it is at its lowest level at 25% weight. At 50 m particle size, the impact of particle size on heat conductivity of composites is clearly visible. When HS filler concentration rises and particle size falls, the dielectric constant of HS- UPE composites increases; it reaches its maximum value at 25% wt and 50m RH particle. On 50 m RH-RTV silicone composites, frequency variation has little impact.