Epoxy‐based multilayers for flame resistant flexible polyurethane foam (FPUF)

Abstract

Flexible polyurethane foam (FPUF), a widely used cushioning and comfort component for homeware and automobile industries if tailored for flame resistance, can exhibit enhanced market value. With the view to preparing such protective films, multilayered coating composed of montmorillonite (MMT) and triphenyl phosphate (tPP) along with polyethyleneimine (PEI), poly[(o-cresyl glycidyl ether)-co-formaldehyde] (CNER), tPP solution and MMT suspension was deposited via layer-by-layer technique so as to suppress the flammability of FPUF. A comparative study applying "cone test" revealed that multilayered coatings having PEI(CNER/NH 2 -MMT/ PEI) n and PEI(CNER/NH 2− MMT/tPP) n architectures, where "n" signifies the number of layer pairs, exhibited remarkable decrease in "peak heat release rate" (pHRR) of 20 and 25%, respectively, as compared to uncoated FPUF. Moreover, these coatings showed a 50% reduction in "fire growth rate index" (FIGRA) when compared to uncoated FPUF. This significant decrease in FIGRA after a specific combination of epoxy-clay features that such multilayered coatings can be used to protect the underlying FPUF due to the labyrinth effect offered by MMT and accelerated char formation by tPP. Furthermore, the evolution of volatile gases upon combustion of multilayered coated foam decreased due to the inhibition of oxygen permeation owing to the protective effect of the coating.

Thin coatings for fire protection: An overview of the existing strategies, with an emphasis on layer-by-layer surface treatments and promising new solutions

“…[ pHRR. [244] The burning length of a PI fabric was reduced with a 20 BL Poly(Nbenzyloxycarbonyl-3,4-dihydroxyphenylalanine)/MMT, even after washing, [245] but a 8 TL PEI/MMT/PAA coating on a barrier fabric was found to be detrimental to the HRR. [209] The same system on PUF only decreased the HRR by 17 %, and while it might seem like an insignificant result, it was one of the first studies of a LbL MMT-based coating on PUF, and it had the advantage of highlighting the interest of the system by showing that with much less FR material, and with an environmental friendly method, results similar to those observed for commercial-used PUF fire retardant fillers were obtained.…”

Mechanically strong waterborne poly(urethane‐urea) films and nanocomposite films

“…[10][11][12][13] Layered silicates are the other popular fillers used for a PU matrix due to the enhanced thermal and flame resistance of the nanocomposites compared to the matrix. [14][15][16] PUs, PUUs, and their nanocomposites based on polycarbonate polyols as a soft phase are used as biocompatible materials with suitable flexibility at low temperature. [17][18][19] They are mainly used as elastomers.…”

“…Due to all of the abovementioned properties, many different materials based on PU and nanosilica have been continuously used as highly advanced current materials with broad potential for applications such as actuators, thermal insulation, flame retardant and corrosion inhabitant coatings, membranes, or coatings for scaffolds 10–13 . Layered silicates are the other popular fillers used for a PU matrix due to the enhanced thermal and flame resistance of the nanocomposites compared to the matrix 14–16 …”