Environmentally friendly construction of a ZIF-8 assisted phosphorus-nitrogen synergistic flame-retardant system on PET fabric

Polyethylene terephthalate (PET) fabrics are highly flammable and generate substantial smoke emissions, necessitating effective flame-retardant treatments. In this study, we developed an environmentally friendly strategy to construct a metal-organic framework (MOF)-assisted phosphorus-nitrogen synergistic flame-retardant system on PET fabric. This was achieved through in situ growth of ZIF-8 via a solvent-saving hot-pressing method, followed by 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) incorporation using a water-saving supercritical CO 2 technique. Comprehensive characterizations and density functional theory (DFT) calculations demonstrated that ZIF-8 enhances the immobilization and stabilization of DOPO on PET through chemical interactions, resulting in a durable flame-retardant material. The treated fabric demonstrated significantly improved fire safety compared to pristine PET, with a higher limiting oxygen index (LOI, from 21% to 31.6%), reduced peak heat release (20.2%), suppressed peak smoke production (54.1%), and lower average CO yield (79.6% reduction). A dual-phase flame-retardant mechanism (condensed and gas phases) was proposed based on systematic analyses. Importantly, the modified fabric retained its mechanical properties and breathability while acquiring additional functionalities including UV resistance and antibacterial properties. This work presents a sustainable and efficient strategy for designing high-performance, fire-safe textiles via MOF assisted synergistic engineering.