Thermal characterization of low density polyethylene (LDPE)/rice husk ash and rice husk ash derived silica aerogel composites

Abstract

In this study, rice husk ash (RHA) and RHA derived silica aerogel were prepared and incorporated into low density polyethylene (LDPE) as a filler (0-10%) forming a composite and the performance of both fillers were compared. The composites were prepared by melt-blending and compression moulding. The effect of differing filler weight percentage on the thermal properties was also determined. Characterization of the fillers was done using X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and a thermal conductivity meter. The prepared composites were characterized using FT-IR and thermal analysis was done using TGA, DSC and a thermal conductivity meter. Both fillers show improvements in terms of the thermal stability of the composite when compared to unfilled LDPE but comparisons between the silica aerogel and RHA shows that silica aerogel’s performance slightly edges the performance of RHA. The incorporation of silica aerogel as filler shows better thermal stability when compared to RHA with a slight increase in onset degradation temperature as the filler percentage increases. In terms of thermal conductivity, the addition of silica aerogel as filler shows an increase in thermal insulation strength of the composite with a reading in the range of 0.0926-0.1820 W/m.K compared to RHA at 0.3275-0.3532 W/m.K and unfilled LDPE samples at 0.3889 W/m.K.