A Facile Method for Flame Retardant and Mechanically Reinforced PET Fabrics Based on Sustainable Components

Polyethylene terephthalate (PET) fabrics are widely used owing to their excellent physical and chemical properties, but their inherent flammability poses a significant threat to safety. To address this issue, this study developed an organic–inorganic hybrid flame-retardant system composed of chitosan (CH)/laponite (LAP)/polyethylenimine (PEI)/phytic acid (PA) and constructed a high-performance fire-resistance coating on PET fabrics via a trilayer assembly technique. The results showed that the coated PET fabrics exhibited excellent flame-retardant performance when the concentration of PEI/PA was 10%. The limiting oxygen index (LOI) reached 29.0%, and the damaged length in vertical burning tests was reduced to 3.5 cm with antidripping ability. Compared to PET fabrics, a decrease of 28.3% in the peak heat release rate (pHRR) and 6.3% in the total heat release (THR) was reached for 10FR@PET. In addition, the CO2/CO ratio exhibited a distinct reduction and decreased from 21.4 to 12.8, indicating effective suppression of toxic smoke generation. Notably, 10FR@PET maintained an LOI value of 28.8% after five standard washing cycles, demonstrating exceptional washing durability. This study provides an easy-to-scale-up approach for developing high-performance and environmentally friendly flame-retardant PET materials with broad application prospects in protective clothing, vehicle interiors, and other decorative fields.