Calcium Borate Particles: Synthesis and Application on the Cotton Fabric as an Emerging Fire Retardant

Abstract

In this study, environmentally benign calcium borate particles (sub-micron size) were synthesized by co-precipitation method and applied on cotton fabric to impart flame retardant property. Synthesized particles were characterized in details to analyze the particle size distribution, crystal structural and chemical constituents. Henceforth, the prepared calcium borate particles were integrated into cotton fabric by following a suitable process condition. Flame retardant efficacy of the treated fabric was analyzed by using vertical flame test and by measuring the limiting oxygen index (LOI) and cone-calorimetry parameters. Besides, particle add-on % on the treated cotton fabric was also optimized (trade-off between efficacy and physiological handle). Optimized concentration of calcium borate particles treated cotton substrate showed a LOI value of around 29 (control cotton fabric having LOI value of 18) and a significant decrease (75% lower as compared to the virgin cotton fabric) in peak heat release rate. Further, thermo-gravimetric analysis and char morphology of control vs. treated substrate were compared to understand the pyrolysis path and carbonaceous structure of cotton substrate, respectively.

Keywords

• calcium borate
• cotton fabric
• cone calorimeter
• flame retardant
• particle synthesis
• thermo-gravimetric analysis