Growth of biobased flakes on the surface and within interlayer of metakaolinite to enhance the fire safety and mechanical properties of intumescent flame-retardant polyurea composites

In this work, meta-kaolinite has been successfully multidimensionally modified by growing melamine-phytate nanoflakes within the interlayer and on the surface of metakaolinite via facile and green supramolecular self -assembly technology. Then, multidimensionally modified metakaolinite (Mul-K-0) along with intumescent flame retardant (IFR) has been incorporated into polyurea (PUA)The incorporation of Mul-K-0 together with IFR into PUA has simultaneously enhanced both the fire safety and mechanical property. Flame retardancy and smoke suppression of Mul-K-0 based PUA/IFR composite have been evaluated by oxyacetylene ablation test, limiting oxygen index, UL-94 vertical burning and conventional or modified cone calorimeter tests. The un-derlying mechanism of Mul-K0 responsible for enhancing the fire safety and mechanical properties were explored. This work offers a new strategy for improving the flame-retardancy efficiency utilizing the synergistic effect of IFR and modified meta-kaolinite and provides a promising opportunity for fabricating long-life flame retardant PUA composites.

Automated summary

In this work, meta-kaolinite was successfully modified by growing melamine-phytate nanoflakes within the interlayer and on the surface of metakaolinite. The modified meta-kaolinite was then incorporated into polyurea, resulting in improved fire safety and mechanical properties. The flame retardancy and smoke suppression of the composite material were evaluated through various tests, and the underlying mechanism for the improved performance was explored. This work provides a new strategy for fabricating long-life flame retardant materials.