Modification of fly ash cenospheres by 3-glycidyloxypropyl trimethoxysilane (GPTMS) for anticorrosive coating applications

The present work focused on the functionalization of fly ash cenospheres (FACs) by GPTMS for anticorrosive applications. FACs are an industrial waste product from coal industry that possesses valuable properties such as lightweight, low water absorption, corrosion resistance, and chemical inertness. Epoxy is one of the best materials for superior corrosion performance and excellent substrate adhesion and therefore was chosen as the base matrix. 3-Glycidyloxypropyl trimethoxysilane (GPTMS) was selected as the suitable silane functionalization agent (with the variation of 2, 4, and 6 wt% of cenospheres due to its compatibility with epoxy resin). GPTMS can help corrosion control by forming dense Si–O–Si networks that act as a protective barrier against water, aggressive ions, etc. FTIR and XRD analyses studied the primary structural confirmation of silane-modified cenosphere, while the morphology was studied by SEM analysis. TGA and DTG curves investigated the thermal properties of the coatings, while EIS studies evaluated the anticorrosive attributes. The EIS results showed that the corrosion rate decreased as the percentage of silane increased in the coating, which indicates the superior anticorrosion behaviour of the 6 GPTMS FAC–epoxy sample compared to others.