Effect of monoethanolamine and silica additives on flame retardant action of diethylphosphatoethyl-triethoxysilane on cellulose based fabric

Recent studies have shown that the combustion behaviour of cellulosic substrates can be strongly affected by the presence of a protective phosphorus-rich silica coating obtained with a promising sol- gel approach. Thus, in the present work, monoethanolamine (MEA) was used in combination of diethylphosphatoethyltriethoxysilane (DPTES) with the aim to investigate both the ability of MEA to neutralize the acidic conditions of DPTES sol before cotton fabric treatment and the fire resistant properties of the obtained coating. Moreover, to study the influence of an inorganic–organic hybrid matrix on the durability of the proposed flame retardant finishing, the DPTES-MEA sol was mixed with tetraethoxysilane (TEOS) and 3-glycidoxypropyltriethoxysilane (GPTES) precursors, to produce hybrid silica coatings on the cotton fibres. Limiting Oxygen Index (LOI), thermogravimetric Analysis (TGA), microscale combustion calorimeter (MCC), were performed on the treated cotton fabrics. The results showed that DPTES-MEA sol is able to enhance the thermal and thermo-oxidative stability of cotton, exploiting the joint effect of thermal shielding (exerted by silica phases) and char-forming.