Phosphorylated chitosan polymer as flame retardant and antimicrobial agents for cotton and cotton-polyester blends fabrics

Flame retardant and antimicrobial agents for treating cotton and cotton-polyester blends fabrics were achieved by environmentally friendly acceptable materials without using halides and formaldehyde. Chitosan as a naturally occurring polymer was modified by reacting with phosphoric acid to produce phosphorylated chitosan polymer (PCSP), which was applied as a fire-retardant towards cotton and cotton-polyester blend fabrics. Also, the antimicrobial studies on treated fabrics were reported. Evaluation of the performance of fire-retardant with different concentrations of phosphoric acid and chitosan was reported. Two important tools (Limited Oxygen Index (LOI) and tensile strength) were investigated to study the rate of burning of fabrics in untreated and treated forms. Furthermore, the surface morphology of fabrics toward untreated and treated forms was studied. The thermal analysis and ATR- FTIR spectra of tested fabrics were reported. The results showed that fabrics exhibit both excellent flame retardant and antimicrobial properties when treated with PCSP solution. Exhibiting an enhanced LOI from 21.5% to 53.2% in case cotton 100% and from 18.6% to 31% in case cotton- polyester blends. The tensile strength of all treated cotton-polyester samples was found to be not changed much with increasing phosphorous content where the value of Elongation (%) of blank cotton-polyester was 24.09 % become 26 % after treated at P11. The formation of a protective layer on the surface of treated fabrics was organized by SEM images, which increased the resistance of treated fabrics to burn. In general, the collected results clarified that, the increasing in phosphoric acid content in PCSP lead to increase in the flammability resistance of the treated samples. LOI, tensile strength, thermal stability confirmed the cross-linking between cellulose and PCSP.