Preparation and damping properties of fly ash filled epoxy composites

With the purpose of characterizing the high damping properties of the promising low density epoxy/fly ash composites, a series of epoxy composites filled with fly ash of different volume fraction are prepared in this work. Damping tests of cured epoxy composites are performed in the temperature range from −40 to 150 °C and in the frequency range from 10 to 800 Hz by using a tension-compression mode. The results show that the values of tangent delta (tan δ) reach their peak values at the glass transition temperatures for the composites with 30–50 vol.% fly ash, and the tan δ values attenuate slowly with the increase of frequency, which indicates that the damping properties of such composites are better than those of other composites. Scanning electron microscopy is used to observe the fractured surfaces of the composites and clarify the dispersion and distribution of fly ash particulates in the matrix. In addition, the thermogravimetric curves are also employed to characterize the heat-resistant performance of the composites.