A Study on the Thermogravimetric and Differential Thermal Analysis of a Bio Based Silica Nano Composite Material

Abstract

The thermal stability of ethanol extract of Dacryodes edulis (DE), precipitated amorphous silica (PAS), and their hybrid (DE/PAS) was evaluated by thermogravimetric/differential thermal analysis (TGA/DTA) between 0–950 °C. Three major thermal events were observed: initial weight loss at ~30–200 °C (physically adsorbed water/volatiles), major decomposition at 300–500 °C (polymer chain degradation, silanol condensation, endothermic peaks), and residual stability beyond 500 °C. Residual mass values were ~15% (DE), ~12% (PAS), and ~10% (DE/PAS). Major weight loss occurred at 350–450 °C (DE), 370–480 °C (PAS), and 380–500 °C (DE/PAS), with peak decomposition temperatures at 400 °C, 420 °C, and 430 °C respectively. The weakest DTA peak intensity in DE/PAS indicated a more controlled degradation process and superior thermal stability. FTIR analysis revealed functional groups (aromatic ester, alkyl aryl ether, O–H, C=C, C=O, anhydride, N=C=S, C≡C, C–H), while TEM confirmed spherical nanoparticles (~20–50 nm) before and after hybridization. The enhanced stability of DE/PAS is attributed to strong covalent interactions between electron-rich groups in DE and Si–O–Si bonds in PAS, conferring improved mechanical strength and thermal resistance. The study provides an anti corrosion additive which can be an excellent alternative to the more toxic material employed in conventional coating hence is of relevance in material science, in the formulation of a high performance coating for appication in areas such as ships and automobiles where strong adhesion, scratch resistance and non wettablity of the coating is crucial. It provides additional insight on further reserach in other relevant areas such as water treatment, removal of heavy metals, drug delivery system, energy storage and conversion systems.