Environmentally-Benign Phytic Acid-Based Multilayer Coating for Flame Retardant Cotton

Area of Science:

• Materials Science
• Textile Chemistry
• Polymer Science

Background:

• Conventional flame retardants often pose environmental and health risks.
• Developing sustainable and benign flame retardant (FR) solutions for textiles is crucial.

Purpose of the Study:

• To impart flame retardant properties to cotton fabric using benign and renewable molecules.
• To evaluate the effectiveness of layer-by-layer (LbL) deposition of phytic acid (PA) and chitosan (CH) with urea for flame retardancy.

Main Methods:

• Cotton fabric was treated using layer-by-layer (LbL) deposition with anionic phytic acid (PA) and cationic chitosan (CH) incorporating urea.
• Flammability was assessed using limiting oxygen index (LOI) and vertical flame testing.
• Combustion behavior was analyzed using microscale combustion calorimetry (MCC) and thermogravimetric analysis (TG).

Main Results:

• Treatments with 10 or more bilayers (BL) rendered cotton self-extinguishing and passed vertical flame tests.
• Average reductions in peak heat release rate (pHRR) and total heat release (THR) were approximately 61% and 74%, respectively.
• Treated fabrics showed increased char residue (~21% at 650 °C) and intumescent behavior, indicating enhanced thermal stability.

Conclusions:

• LbL deposition of PA/CH-urea offers a safe and effective flame retardant finish for cotton.
• This sustainable approach provides a viable alternative to conventional flame-retardant treatments.
• The method's efficiency with relatively few layers makes it industrially relevant.