Bio-template synthesis of MgAl layered double hydroxide with enhanced flame retardant property for leather finishes

In order to impart the leather with efficient flame retardancy, MgAl layered double hydroxide nanomaterial was synthesized by using bio-based caprolactam modified casein as the template (Temp@MgAl-LDH) via coprecipitation method, then it was blended with modified casein emulsion and applied as flame retardant in leather finishes. By tuning the size of the biomass template, MgAl-LDH was successfully grown on the template. The structure and morphology of Temp@MgAl-LDH were characterized by XRD, XPS, SEM, and TEM, and it was proved that the crystal structure of Temp@MgAl-LDH was complete, and the lamellae also grew well on the surface of the casein micelle. In addition to this, the result of the limit oxygen index (LOI) and the cone calorimeter (CONE) on finished leather illustrated that the flame retardancy of leather increased with the increase of Temp@MgAl-LDH content. When the content of the Temp@MgAl-LDH was 5%, LOI of leather can reach by 28.5%, and smoke density decreased obviously after introducing Temp@MgAl-LDH. This as-prepared composite will be a good candidate as green flame retardant or smoke suppressant that can be used in adhesives, coatings, and other fields.