Enhancing the fire barrier performance of cotton fabrics via polyamidoamine-based coatings

This study investigates the potential of enhancing the fire barrier performance of cotton fabrics by combining α-amino acid-based polyamidoamines (PAAs) with different charge distribution, recognized for their charforming ability, with smectites of varying aspect ratios. To this purpose, various PAAs coating formulations were applied to cotton fabrics and assembled with polyurethane foam within a mockup assembly to be evaluated under forced combustion conditions (75 kW m⁻²) in the Cube test. Preliminary tests on six PAAs and four smectites identified the cationic, arginine-derived PAA (M-ARG), known for its strong interaction with sodium montmorillonite, as the most promising candidate when combined with laponite. While PAAs alone did not significantly improve barrier performance, the M-ARG/laponite combination (total 16 % by mass add-on) delayed foam liquefaction and the release of liquid pyrolyzates from polyurethane foams by about 21 s. The correlation between the results obtained from Cube test and full-scale chair mockup test, confirmed that treated fabrics can delay the fire growth and the heat release peak rate by over two minutes. These findings demonstrate the effectiveness of char-forming nanocomposite coatings in enhancing fire barrier performance and validate the Cube test as a reliable, cost-efficient, and practical method for material development, reducing the reliance on extensive full-scale testing.