Waste material fly ash as an alternative filler for elastomers

Fly ash (FA), a by-product of the power generation industry, can potentially be used as a filler in polymer products. Particularly, FA has been investigated as an alternative filler to partially or fully replace commercial fillers in polymer composites. This mini-review discusses the fundamental properties of FA, environmental pollution from commercial fillers, and the performance of FA in polymers. The properties of FA-loaded polymer composites are discussed, including the morphological, rheological, mechanical, and thermal properties. This review highlights the potential methods and challenges for substituting, or replacing, commercial fillers in various polymers such as natural rubber (NR), epoxidized NR, epoxy, styrene-butadiene rubber (SBR), NR/SBR blends, polyethylene, polypropylene, and polyester.