This is the most comprehensive evaluation of Layer-by-Layer (LbL) coatings intended to reduce the flammability of polymeric materials. Through a systematic variation of the coating recipe, an ideal combination of the coating attributes was identified that provides a rapidly developing coating with an optimum balance of flammability, mechanical, and physical attributes on a complex 3D substrate, polyurethane foam (PUF). Using a unique trilayer (TL) assembly approach, the coating growth was significantly accelerated by the polymer (poly(acrylic acid) (PAA)/branched polyethylenimine (BPEI)) concentration in the formulation. However, to significantly reduce flammability without compromising other performance attributes, the concentration of the nanoparticle fire retardant (nanoFR, clay) solution was critical. This study has resulted in the most significant reduction in PUF flammability using LbL technology without compromising any of the mechanical or physical attributes of the PUF. More specifically, a reduction of peak heat release rate (pHRR) and average heat release rate (aHRR) of 33% and 78%, respectively, which is at least two times more effective than commercial fire retardants and other LbL FR coatings for PUF. The insights gained through this research are expected to accelerate the development of other LbL coatings regardless of the intended application.
Citation: Journal of Materials Chemistry
Pub Type: Journals
Layer-by-Layer, Polymer Clay Nanocomposite, Polyurethane foam, Flame Retardant, Heat Release Rate, Furniture, Montmorillonite