Environmentally friendly starch-based wood wallpaper with simultaneously flame-retardant and mildew-resistant properties

Wallpaper is widely used in indoor decoration, but its flammability and susceptibility to mold caused by the starch-based adhesive widely used in wallpaper is a major problem restricting its application. In this study, environmental friendly Wood Wallpaper was prepared by starch adhesive incorporated with bio-based three-source-integration flame retardant (HSt-PAPI) which was integrated with hydrolyzed starch (HSt) as carbon source, phytic acid (PA) as acid source and piperazine (PI) as gas source. The HSt-PAPI was prepared by synthesizing piperazine phytate (PAPI) through an ionic reaction between phytic acid and piperazine, followed by the introduction of hydrolyzed starch. To be compatible with the eco-friendliness of starch adhesive employed in wallpaper, natural anti-mildew agents like citral (CT), cinnamaldehyde (CA), tea polyphenol (TP) and chitosan-Ag (CS-Ag) were selected to improve the mildew resistance properties. The results indicated that with 30 wt% addition of HSt-PAPI, the wallpaper could achieve V-0 grade of UL-94, 36.6 % of LOI (Limiting Oxygen Index) and 14.88 MJ/kg of gross heat of combustion (PCS). In the mildew resistant test, with 3 % concentration for both CS-Ag and cinnamaldehyde (CA), the mildew resistance was exceeded 75 %. The inhibition zone was greater than 7 mm. This research provides an environmentally friendly and sustainable route for the fabrication of multi-functional interior wood wallpaper decorative materials.