Preparation and properties of highly efficient flame-retardant Lyocell fabrics: Mitigating the acidity effect of phytic acid on the mechanical properties under pad-dry-curing process finishing conditions

The pad-dry-curing process involves padding with finishing liquid, pre-drying, and high-temperature baking. It is widely used in the dyeing and finishing field. For the field of flame-retardant finishing of fabrics, the use of phytic acid (PA) as a raw material can be highly effective. However, the extreme acidity of PA can cause damage to cellulose-based fabrics under high-temperature conditions. The development of PAMA, a compound formed by reacting PA with maltitol, can effectively alleviate the damage of PA to fabrics at high temperatures. PAMA not only exhibits excellent flame-retardant properties by slowing down flame propagation but also helps mitigate the acidic damage to Lyocell fabrics during the pad-dry-curing process, including an increase in the limiting oxygen index (31.9%), a reduction in peak heat release (55%), and a substantial increase in breaking force retention compared with those of the sample using pure PA as a flame retardant (300%). Overall, this research presents a promising approach to the development of environmentally friendly flame retardants for textiles, highlighting the importance of balancing effectiveness with fabrics.