Optimisation of Fire-Retardant Finishing of Cotton with Ammonium Sulfamate and Sodium Stannate by User-Defined Quadratic Empirical Model

The present work describes the application of an eco-friendly statistically optimized fire-retardant (FR) finish on cotton woven fabric with ammonium sulfamate (AS) and sodium stannate (SS). FR properties were investigated in terms of Limiting Oxygen Index (LOI), char length, % loss of fabric tenacity along with other physical properties. Based on the preliminary experimental study, two important input variables were identified as concentration of AS and concentration of SS. By applying “Response Surface Methodology” (RSM) with the “User Defined Quadratic Empirical” (UDQE) model of the statistical experiment of design at 5 levels of each important input variable, optimum concentrations of each input variable were determined. By using a suitable regression equation, optimum FR properties were predicted. Preliminary experimental results with different concentrations of AS and SS (keeping total added chemical around 20–24%) rendered the best FR performance at 16% AS and 8% SS combination showing a synergistic with LOI value 38+ , char length around 6.6 cm with approximate 30% loss of fabric tenacity. The optimized data were nearly matching with the experimental results confirming best best-fitted statistical model for these input variables at comparable conditions of treatment. Analysis of SEM, FTIR, and TGA for optimized samples was also reported to understand the reaction mechanism. Improvement of wash stability by the addition of a small amount of zinc acetate (5%) as a catalyst was also studied.