Preparation and characterization of thermoplastic starch composites with fly ash modified by planetary ball milling.

•The modification of fly ash was carried out by dry grinding in a planetary ball mill.•TPS composites were prepared containing different amounts of UFA or MFA powder.•The maximum tensile strength of TPS was obtained with a 2.50% loading of MFA.•MFA improved water resistance and delayed the degradation processes of TPS.•FA, acting as a catalyst, speeds up the thermal destruction of the materials.