Submitted to: International Journal of Materials Science and Applications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/25/2019
Publication Date: 10/23/2019
Citation: Chang, S., Condon, B.D., Smith, J.N., Nam, S. 2019. Innovative approach to flame retardant cotton fabrics with posphorous rich casein via by layer-by-layer processing. International Journal of Materials Science and Applications. 8(5):81-89. https://doi.org/10.11648/j.ijmsa.20190805.12.
Interpretive Summary: Interest in developing new flame retardant systems for cotton containing materials has increased in the last 10 years due to environmental and toxicological concerns associated mainly with existing halogenated systems. This work demonstrates early results which indicate that simple common chemicals containing nitrogen and phosphorus can be applied to cotton fabrics in conjunction with a casein milk protein nanoparticle/polymer coating process. Flammability and thermal decomposition of the treated fabrics is greatly reduced. A commercially viable process for treating fabrics continuously is presented.
Technical Abstract: Flame retardant behavior prepared by the layer-by layer assemblies of phosphorous rich casein milk protein with eco-friendly inorganic chemicals on cotton fabrics. The cotton twill fabrics prepared with solutions of mixture of positively charged branched polyethylenimine (BPEI) with urea, diammonium phosphate (DAP), and negatively charged casein. Layer-by-layer assemblies for flame retardant properties were applied by the pad dry cure methods and each coating formula was rotated by 20 bi-layers. It was to assay their effectiveness to resist flame spread on treated fabrics using vertical (ASTM D6413-08) and 45° angle flammability test (ASTM D1230-01) methods. In most of case, char lengths of fabrics that passed the vertical flammability tests were less than 50% of original length and after-flame and after-glow times were less than one second. We tested the extent of char produced by untreated and treated fabrics at 600°C by thermogravimetric analysis and limiting oxygen indices (LOI, ASTM D2863-09). All untreated fabrics showed LOI values of about 21% oxygen in nitrogen. LOI values for the treated casein with BPEI/urea/DAP fabrics were greater than 29-34% between 5.80-9.59 add on wt%. Their structural characterizations by TGA/FT-IR and SEM methods will be shown. The treated fabrics exhibited improved thermal stability, as evidenced by increased ignition times and lower heat release rates. The result of this study show that flame retardant nanocoatings can be readily applied to textile fabrics using a continuous process that is ideal for commercial and industrial applications.