Egg white proteins/lignin-DAP intumescent multilayer nanocoating for flame retardant cotton fabric

Abstract

An environmentally benign nanocoating for flame retardant cotton was developed by pairing positively charged egg white proteins (EWP) and a negatively charged mixture of magnesium lignosulfonate (LS)–diammonium phosphate (DAP) solution. Egg white proteins are cheap and easy to prepare nitrogen-containing polyelectrolytes with strong char ability. Five bilayers of 0.5 % EWP3/(1 % LS–10 % DAP)4 add 6.8 % weight gain and impart self-extinguishing behavior to cotton on a vertical and horizontal flame test. This nanocoating, which creates a conformal cover of cotton fibers, reduces peak heat release by 60.1 %, total heat release by 59.3 %, and fire growth capacity up to 81.5 %. The results of this investigation show the potential of EWP to be used as a char-forming material with high nitrogen content in intumescent systems.