A combined theoretical and experimental investigation of the valorization of mechanical and thermal properties of the fly ash-reinforced polypropylene hybrid composites

Fly ash (FA) particles were surface modified with cetyltrimethylammonium bromide (Ctab) and hybridized with graphene oxide (GO) and carboxymethyl cellulose (CMC) separately to increase interfacial adhesion with the polypropylene (PP) matrix. For a 5 wt.% CMC-hybridized FA, and Ctab-treated FA-filled PP composite, the highest increase in tensile (13% and 7%) and flexural (30% and 25%) strength was observed compared to pristine PP. The functionalization on FA surface was confirmed by ATR-IR analysis. Morphological study using FE-SEM showed that FA particles were successfully carried on to CMC and GO surfaces. An increment in melting temperature by ~ 3 °C was obtained. Improved thermal stability of the composites was confirmed from TGA analysis. The molecular dynamics (MD) simulations were carried out for all the three modification and it predicted highest interfacial interaction in case of Ctab-FA-reinforced PP composite.