Synthesis of a novel highly efficient flame-retardant coating for cotton fabrics with low combustion toxicity and antibacterial properties

The synthesis of multi-function flame retardants is widely increasing to fulfill industrial and economic goals. In this work, a novel flame retardant, melamine salt of tannic phosphate (MTP) was prepared and characterized. MTP was mixed with polyvinyl alcohol (PVA) solution and used as a coating for cotton fabrics. In addition, tannic acid (TA) and melamine phosphate (MP) were mixed with PVA solution and applied as a coating for cotton fabrics. Vertical and horizontal flammability tests showed that the flame did not propagate in samples treated with PVA/MTP. In contrast, samples treated with PVA/TA/MP burnt completely. Limiting oxygen index (LOI) data indicated that samples treated with PVA/30%MTP reached LOI value 68.4%, while the control sample had LOI value 17.1%. Smoke density results presented that PVA/MTP succeeded in reducing the maximum specific optical density (Ds (max)) of cotton fabrics. FTIR gas analyzer results manifested that the addition of PVA/MTP to cotton fabrics decreased the emission of CO, CO2, C3H8, C2H6, C6H14, and formaldehyde in the gas phase. Fractional effective dose (FED) and lethal toxic potency (LC50) showed that samples coated with PVA/MTP are less toxic than blank. In addition, these fabrics exhibited a remarkable antibacterial property against gram-positive and gram-negative bacteria.