Modification of Soybean Meal Degradation Products to Achieve Durable Flame-Retardant Finishing of Cotton Fabrics

Conventional flame-retardant textiles often rely on halogenated or formaldehyde-based chemicals, raising environmental and health concerns. This study explores a sustainable alternative by developing a novel, durable, and halogen- and formaldehyde-free flame retardant (PmS) derived from soybean meal through degradation and chemical modification. The key innovation lies in creating a high-performance, bio-based flame-retardant finish that integrates durably into cotton fabric while maintaining essential textile properties. By applying 90 g/L PmS, the treated cotton fabric achieved an exceptional limiting oxygen index (LOI) of 29.2%, a significant reduction in char length to 68 mm, and retained a self-extinguishing LOI of 25.3% even after 50 laundering cycles. Comprehensive characterization (FT-IR, XPS, SEM, EDS) confirmed successful chemical bonding and penetration within the fibers. Cone calorimetry further demonstrated substantial fire safety improvements, with reductions in total heat release and peak heat release rate by 29.7% and 81.12%, respectively, supported by char residue analysis indicating a condensed-phase flame-retardant mechanism. Critically, the treated fabric preserved satisfactory softness, mechanical strength, and breathability. This work successfully establishes a viable and eco-conscious strategy for durable flame-retardant finishing of textiles using renewable biomass.