Synchronous preparation and modification of LDH hollow polyhedra by polydopamine: Synthesis and application

[Display omitted] •ZIF-67 was etched to produce CoCo-LDH while coated by organic polydopamine (PDA) concomitantly. A PDA modified hollow cage lamellar LDH nanostructure loaded with TPP was constructed (TPP@LDH@Co-PDA).•Polydopamine enhanced compatibility between flame retardants and the matrix, boosting mechanical strength.•An inspiration for enhancing the thermal stability and compatibility of LDH, and to solve the migration problem of phosphorous small molecules. Layered double hydroxides (LDH) have irreplaceable advantages in the field of polymer flame retardancy, but their thermal stability and compatibility with matrix still need to be improved. In this paper, the bottom-up method is adopted, and the phosphorus series flame retardant triphenyl phosphate (TPP) was first encapsulated inside ZIF-67. On this basis, ZIF-67 was etched to produce LDH while modified by polydopamine (PDA) concomitantly. An organic coated polydopamine hollow cage lamellar LDH microstructure loaded with TPP was constructed, and its structure-performance relationship was verified. When 2 wt% TPP@LDH@Co-PDA was added to the epoxy resin, the LOI value of the composite was increased to 29.4 %, the peak heat release was reduced by 43.1 %, and the smoke release was significantly reduced. The unique microstructure endows epoxy composites with good flame retardancy, improves mechanical properties, and provides a new solution to the migration problem of phosphorous based flame retardants.