Comparison between experimental and theoretical thermal conductivity on epoxy based aluminium hydroxide and silica aerogel composite materials

Abstract

The aerogels are having nanoparticles that are connected to form a freely connected 3D network, leaving a high fraction of space in between nanoparticles. In between a high fraction of space is called porosity, and due to this high porosity, aerogel material has an exceptional property such as low dielectric constant, low density, and very low thermal conductivity. Thermal conductivity plays a vital role in the thermal property of polymer composite materials and also plays an essential role in calculating the heat conduction as an insulation application. The silica aerogels have limited use as thermal insulation material because of its high cost. The present research work aims to study the thermal conductivity of reinforcing materials as aluminium hydroxide and silica aerogels mixed with epoxy resin as matrix material. Aluminium hydroxide/ silica aerogels of different compositions in the epoxy resin are used for the preparation of composite specimens. Finally, the heat flow guarded meter test method was used to evaluate the thermal conductivity of different composition of polymer composites. Related theoretical models were deduced based on the equal law of the specific thermal conductivity and law of minimal thermal resistance. The experiment measured values of thermal conductivity compared with the value of theoretical models thermal conductivity are relatively close. This study has shown that the aluminium hydroxide mixed with epoxy matrix results in significant increases in heat conductivity to use in heat sink application and silica aerogels mixed with epoxy effect in decreases heat conductivity thereby improving its thermal insulation ability to use insulation application.