Combination Intumescent and Kaolin‐Filled Multilayer Nanocoatings that Reduce Polyurethane Flammability

Abstract

Chitosan (CH), ammonium polyphosphate (APP), CH and poly(acrylic acid) (PAA)‐stabilized kaolin (KAO) clay are deposited as quadlayers onto the surface of flexible polyurethane foam (PUF) via layer‐by‐layer assembly in order to improve the fire resistance of the foam. The effectiveness of this nanocoating on flame suppression is compared to control films without KAO and bilayer coatings. PUF coated with only five CH/APP/CH/PAA‐KAO quadlayers (around 184 nm thick) maintains its open porous structure and self‐extinguishes upon exposure to a butane torch flame for 10 s. Cone calorimetry reveals that this coating reduces the peak heat release rate and total smoke release by 66.8% and 59.3%, respectively, compared with uncoated foam. Thermogravimetric analysis under nitrogen indicates the combination of intumescent components and clay promotes char formation and improves the thermal stability of the polyurethane substrate. This multilayer coating has the potential to improve the fire safety for PUF, commonly used in home furnishings, and a variety of other polymeric substrates.

Improving the flame retardant properties of polyester‐cotton blend fabrics by introducing an intumescent coating via layer by layer assembly

“…The 1 wt% APP was added into DI water and the PH value was adjusted according to previous literature. [13] APP solution was used for deposition immediately upon preparation. [17]…”

“…The incorporation of intumescent coating and melamine slightly increase the smoke generation of the fabric in the heat radiation process, which has been observed in the previous work. [13] The reason can be attributed to the incorporation of flame retardant coating leads to an intumescent char formation in the condensed phase, which acts as a protective layer on the surface of the PET-COT matrix and causes incomplete combustion. Besides, the addition of MEL can also release inflammable gases.…”

“…via LbL assembly technique. [13] Although LbL coating has various superiorities, none of us can deny its relatively low efficiency is still a persistent problem. [14] The goal of LbL assembly technique is to find a more effective system to impart better performance with shorter processing time and lower weight gain.…”

Halogen‐Free Coatings Combined with the Synergistic Effect of Phytic Acid and Montmorillonite for Fire Safety Flexible Polyurethane Foam

“…Because of its unique porous structure and organic constituents, FPUF contains the DOI: 10.1002/mame.202100930 main trigger conditions of the dangerous conflagration which are larger ignition area and flammable components. [7][8][9] Even, oneroom setting with furniture and bedding which are filled with FPUF is capable of occurring flashover once ignited. [5] Hence, it fails to meet the requirements of materials used in higher fire-safety occasions.…”

Effects of Graphite Oxide Nanoparticle Size on the Functional Properties of Layer-by-Layer Coated Flexible Foams

“…This particular structure has been proved to significantly increase the flame retardancy of PU foams due to a combined effect of heat shielding/reradiating and delayed release of combustible volatiles [25,26]. Although most of the developed coatings have been focused on the exploitation of mineral nanoplates such as montmorillonite [25], vermiculite [27] and kaolinite [28], recent reports showed that oxidized graphitic materials can endow superior flame-retardant properties [21]. Indeed, it has been demonstrated that an LbL coating comprising of six bi-layers (BLs) alternating chitosan (CHIT) and graphite oxide (GO) nanoplates can improve the flame retardancy of PU foams by limiting the flaming ignition in forced combustion tests and suppressing the melt-dripping phenomenon during flammability tests [22].…”