Fabrication of eco-friendly and multifunctional sodium-containing polyhedral oligomeric silsesquioxane and its flame retardancy on epoxy resin

Considering the reduction of fire hazards associated with the application of epoxy resin (EP) composites. Herein, a novel sodium-containing polyhedral oligomeric phenyl silsesquioxane (Na-Ph-POSS) has been synthesized through hydrolysis condensation. FTIR, NMR and MALDI-TOF MS results reveal that Na-Ph-POSS is a hepta-phenyl POSS consisting of Si–O–Na and Si–OH groups. Compared to pure EP, according to the combustion results, the peak of heat release rate (p-HRR), the maximum smoke density (Ds, max) and the peak of CO production rate (p-COP) of EP/5 wt% Na-Ph-POSS significantly decrease by 45.9, 45.1 and 46.9%, respectively. Additionally, EP composites endowed with Na-Ph-POSS have low dielectric constant and dielectric loss. Therefore, eco-friendly multifunctional Na-Ph-POSS provides a promising prospect for mitigating the fire hazards of EP composites.