Bioinspired phosphorus functionalized polycarbazole as highly potent flame retardants and hydrophobic material for smart textile applications

Creating long-lasting, environmentally friendly, and fire-resistant materials using biomass derivatives remains a significant challenge in fire safety and prevention. This study addresses this challenge by developing novel, naturally derived coatings that enhance the fire resistance of textiles. Specifically, carbazole was polymerized in situ using benzoyl peroxide, with phosphoric acid facilitating both polymerization and functionalization to produce phosphorous-functionalized polycarbazole (P@PCz). This material improves the hydrophobicity and flame retardancy of cotton fabric. The study also involved the extraction of carbazole from Murraya koenigii bioresources, producing bioinspired phosphorus-functionalized polycarbazole (BP@PCz), achieving similar results. The synthesized nanocomposite-coated cotton fabric demonstrated exceptional flame-retardant and hydrophobic properties. Notably, P@PCz-coated cotton fabrics withstood continuous flame exposure for up to 585 s, compared to 62 s for PCz-coated fabrics and just 14 s for blank fabrics. Flame retardancy was further evaluated using the limiting oxygen index (LOI) and vertical flammability tests, with P@PCz-coated fabrics achieving an LOI value of 40.4%, significantly higher than the 23.2% for PCz-coated fabrics. Additionally, the water contact angle of P@PCz-coated cotton fabric was measured at 121.39°, indicating excellent hydrophobic properties. This study presents a novel approach for the rapid, large-scale synthesis of P@PCz, demonstrating its potential for various sustainable chemical applications, including enhanced hydrophobicity, and flame retardancy. The use of bioinspired materials in this work paves the way for the development of eco-friendly flame-retardant polymeric materials. Graphical abstract