Bioinspired polyimide film with fire retardant and gas barrier properties by gravity‐induced deposition of montmorillonite

Flame retardants play a crucial role in improving the flame retardant properties of polymer materials. In recent years, environmental problems caused by have attracted widespread attention. It is urgent to use green and effective methods prepare polymers. Bioinspired nanocomposites with layered structures seem provide ideas, but general, their hydrophilic raw materials limit applications certain fields. Here, we prepared biomimetic composites “brick-and-mortar” structure gravity-induced deposition using polyimide as matrix montmorillonite (MMT) filler. The well-arranged composite material could isolate oxygen prevent combustible gases from escaping. gas barrier performance has been greatly improved, which water vapor transmission rate decreased 99.18% three orders magnitude, respectively. also its limiting index can reach 67.9%. be converted water-insoluble thermal imidization water-soluble poly (amic acid) salt precursors, endows low hygroscopicity. coating containing MMT protect against polyurethane (PU) foam fire. During conical calorimetric test, coated sample self-extinguished, peak heat release rate, total release, smoke production are significantly 53.39%, 40.69%, 53.03%, Taking advantage these properties, this work utilizes facile method moisture absorption, excellent retardancy, great application potential.