Phosphonitrile-modified biomass multi-crosslinking strategy: Construction of flame retardant, smoke suppressive and antibacterial polyvinyl alcohol composites

To solve the problems of flammability, large smoke production and easy breeding of bacteria, polyvinyl alcohol (PVA) was modified by a multi-crosslinking structure fabricated by hexachlorocyclotriphosphazene derivative (SHCP) and chitosan (CS) followed by copper ions chelation. In terms of flame retardancy, the peak heat release rate (PHRR) and total heat release (THR) of the modified PVA composites decreased by 52.38% and 24.22%, while the LOI value and char-forming ability were greatly improved. The total smoke production (TSP) of the treated sample decreased by 91.00%. Furthermore, the inhibition rate of modified PVA composites against E. coli and S. aureus was as high as 99.67% and 92.45%. The current work provided a sustainable and versatile advanced strategy for the design of environmentally friendly, and cost-effective flame retardant, smoke suppression and antibacterial PVA composites, which was expected to be applied in the packaging field.