W. Wang, H. F. Pan, Y. Q. Shi, B. Yu, Y. Pan, K. M. Liew, L. Song and Y. Hu (2015) Sandwichlike Coating Consisting of Alternating Montmorillonite and beta-FeOOH for Reducing the Fire Hazard of Flexible Polyurethane Foam. Journal/Acs Sustainable Chemistry &, Engineering 3 3214-3223. [In English]
Web link: http://dx.doi.org/10.1021/acssuschemeng.5b00805
Keywords: Layer-by-layer assembly, Montmorillonite, beta-FeOOH nanorods, Fire, hazard, Mechanism, FLAME-RETARDANT, THERMAL-STABILITY, FILLED COATINGS, FLAMMABILITY, COMBUSTION, GRAPHENE, CLAY, NANOCOMPOSITES, POLYPROPYLENE, DEGRADATION
Abstract: A novel nanocoating, composed of montmorillonite (MMT) nanosheets and beta-FeOOH nanorods, was deposited on the surface of flexible polyurethane (FPU) foams through a layer-by-layer assembly technique to reduce its flamability. The coating growth was performed by alternately immersing FPU foams into polyethylenimine (PEI) solution, MMT-alginate suspension, and beta-FeOOH dispersion. Structural and morphological characterization indicated that MMT nanosheets and beta-FeOOH nanorods were distributed homogeneously on the surface of the matrix and formed a sandwichlike topology. The coated FPU foams showed the lower peak heat release rate (PHRR), compared to the counterparts fabricated by introduction of MMT nanosheets or beta-FeOOH nanorods alone. Furthermore, the concentration of volatile products released from the coated FPU foams was reduced remarkably, indicating that the binary components had tremendous advantages in reducing the flamability of the material. These significant improvements in flame retardancy and toxic gas suppression could be attributed to the following: the MMT-based layers and the network formed by beta-FeOOH nanorods exhibited a "labyrinth effect" to retard the permeation of heat, oxygen, and mass between the flame and underlying FPU matrix.

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