Thin films of fully renewable and environmentally benign electrolytes, cationic chitosan (CH) and anionic phytic acid (PA), were deposited on cotton fabric via layer-by-layer (LbL) assembly in an effort to reduce flammability. Altering the pH of aqueous deposition solutions modifies both thickness and composition of the final nanocoating. In a vertical flame test, fabrics coated with high PA content multilayers completely extinguished the flame, while uncoated cotton was completely consumed. Microcombustion calorimetry confirmed that coating fabric reduces peak heat release rate (pkHRR) by at least 50% relative to the uncoated control. This superior performance is believed to be due to high phosphorus content that enhances the intumescent behavior of these nanocoatings. None of these coatings exceeded 50 nm in thickness with 30 CH/PA bilayers deposited.  These results demonstrate the first completely renewable intumescent LbL assembly, which conformally coats every fiber and provides an effective alternative to current flame retardant treatments.

Intumescent multilayer nanocoating, made with renewable polyelectrolytes, for flame-retardant cotton

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.