Phosphamide-Based Washing-Durable Flame Retardant for Cotton Fabrics

Area of Science:

• Materials Science
• Textile Chemistry
• Polymer Chemistry

Background:

• Flame retardants are crucial for enhancing textile safety.
• Existing flame retardants often contain formaldehyde or lack durability.
• Development of eco-friendly and durable flame retardants is a significant challenge.

Purpose of the Study:

• To synthesize and characterize a novel formaldehyde-free reactive flame retardant.
• To graft the flame retardant onto cotton fabrics and evaluate its performance.
• To investigate the flame retardancy mechanism and durability of the treated cotton.

Main Methods:

• Synthesis of ammonium salt of triethylenetetramine phosphoryl dimethyl ester phosphamide phosphoric acid (ATPEPDPA).
• Characterization using NMR, FT-IR, and SEM.
• Evaluation of flame retardancy via Limiting Oxygen Index (LOI) and cone calorimetry.
• Assessment of durability through 50 laundering cycles.
• Thermogravimetric analysis (TG) and TG-IR for mechanism study.

Main Results:

• ATPEPDPA was successfully grafted onto cotton via -N-P(=O)-O-C covalent bonds.
• Treated cotton achieved an LOI of 44.6% with excellent flame retardance.
• High washing resistance was observed after 50 laundering cycles.
• Flame retardancy operates via a condensed mechanism.
• Physical properties and hand feel of the cotton were well-preserved.

Conclusions:

• ATPEPDPA is an effective formaldehyde-free reactive flame retardant for cotton.
• The unique chemical structure of ATPEPDPA enhances bond stability and durability.
• The treated cotton demonstrates superior fire safety and wash durability without compromising fabric quality.