Surface integration of polyelectrolyte and zeolitic imidazolate framework-67 for multifunctional poly (lactic acid) non-woven fabrics

• A polyelectrolyte (APTris) and ZIF-67 were coated on poly (lactic acid) nonwovens. • The coated fabric had flame retardant, antibacterial and UV-resistant properties. • APTris and ZIF-67 showed excellent synergistic effect in promoting char formation. • ZIF-67 endowed the fabric with antibacterial and UV resistant properties. Eco-friendly bio-based poly (lactic acid) (PLA) non-woven fabrics (NFs) presents great potential to replace petroleum-based fabrics, whereas the attention for preparing multifunctional PLA NFs is still scarce at present. Herein, PLA non-woven fabrics were surface treated by a padding process with polyelectrolyte (APTris) followed by an in-situ growth with zeolitic imidazolate framework-67 (ZIF-67) to improve the flame retardant, antibacterial and ultraviolet (UV) resistant properties. The flammability characterization of the PLA/APTris/ZIF67 fabric sample indicated that the limited oxygen index value was increased to 27.5% from 18.1%. The introduction of APTris/ZIF67 significantly decreased the damaged area, heat release rate, and peak heat release rate of the sample by 83.0%, 33.1%, and 26.4% respectively. It was suggested that APTris and ZIF-67 synergistically promoted the formation of dense char layers, which inhibited the flame spread and reduced the smoke release by adsorption and catalysis effects. Besides, the treated non-woven samples exhibited UV resistant properties and specific antibacterial actions against gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli). This unique surface modification with the combination of APTris and ZIF-67 provides a new opportunity for manufacturing multifunctional PLA non-woven fabrics.