Industrial-grade coal fly ash hollow microspheres from a power station showed to improve fire performance of epoxy resin. Coal fly ash is mainly aluminium silicates, mostly as hollow microspheres c. 15 µm. Loadings of 2 – 10% w/w of flay ash with different densities were tested in epoxy resin CYD-128. The ash was first acidified in 3% oxalic acid then surface modified with silane coupling agent KH570 (3-(methacryloyloxy) propyltrimethoxysilane. Fire performance was significantly improved, e.g. peak heat release rate decreased by over one third with optimum 8% fly ash microspheres. Fire performance effect was due to generation of a complete and corrugated char layer. Flexural strength of the epoxy was however significantly deteriorated.
“Study on the effect of the density and incorporation amount of coal fly ash hollow microspheres on the fire performance of epoxy resin”, J. Liu et al., Materials Today Communications 34 (2023) 105213 https://doi.org/10.1016/j.mtcomm.2022.105213