Lignin-based flame retardants chelated with Fe3+: Facilitating the development of flame retardant, UV resistant and antibacterial properties polyvinyl alcohol composites

Abstract

To overcome the problems of inflammability, poor UV resistance and susceptible to bacterial growth of polyvinyl alcohol (PVA), a new lignin-based PVA composite (PVA/PLig-Fe) was prepared. Compared to PVA, the limiting oxygen index (LOI) of PVA/PLig-Fe was increased by 64.8 %. The peak heat release rate (PHRR) and total heat release (THR) were reduced from 247.40 kW/m2 and 8.26 MJ/m2 of pure PVA to 151.70 kW/m2 and 6.95 MJ/m2, respectively. In addition, the total smoke production (TSP) of the modified sample was reduced from 3.11 m2 to 1.87 m2 compared with PVA. Notably, the elongation at break and tensile strength of PVA/PLig-Fe increased from 188 % and 35 MPa to 247 % and 53 MPa, and its transmittance of UVA (TUVA) and transmittance of UVB (TUVB) were reduced to 0.54 % and 0.59 %, respectively. Besides, the treated samples demonstrated 99.95 % and 99.90 % antibacterial activity against E. coli and S. aureus, respectively. The present research provides a feasible approach for the development of flame retardant, enhanced mechanical properties, UV resistant, and antibacterial PVA composites as a promising application in packaging.