Acid-Doped Biopolymer Nanocoatings for Flame-Retardant Polyurethane Foam

Abstract

Soft furnishing fires contribute to 29% of fire causalities and $8.7 billion in direct property damage annually in the United States. Polyurethane foam (PUF), a common component in soft furnishings known for its comfort and flexibility, can emit toxic gases and propagate fires due to melt dripping when ignited. Various acid salts were added to a layer-by-layer assembled nanocoating, consisting of chitosan and carboxymethyl cellulose, to improve PUF flame retardancy and to understand the influence of salt-doping on flammability. The 20-bilayer phosphoric acid-doped coating exhibits a self-extinguishing behavior, with a 67% reduction in peak heat release rate while maintaining the structural integrity of the foam. By depositing this completely environmentally sourced coating on PUF, the inherent danger of soft furnishing fires can be significantly reduced in a nontoxic manner.

Synergistic Fire Resistance of Nanobrick Wall Coated 3D Printed Photopolymer Lattices

“…Thermoplastics such as poly(methyl methacrylate), as well as thermosets like polyurethane foam have significantly lower degradation temperatures than the studied PR48 resin, despite being an acrylate-based resin. 37,44,45 This is likely due to SR 494 being incorporated into PR48. SR 494 is a derivative of pentaerythritol, a known flame retardant and char promoter.…”

“…Inhomogeneity of elastic modulus of printed parts through the z-axis has been previously demonstrated and is presumed to be a result of unequal conversion throughout a layer. 37,44,45,47 It has previously been shown in other cross-linked networks that thermal expansion changes as a function of conversion. 48 The poor interlayer adhesion, paired with the unequal thermal stresses, is a plausible culprit for the preferential orientation of printed part failure.…”

Synergistic Adenosine Triphosphate/Chitosan Bio-coatings on Polyurethane Foam for Simultaneously Improved Flame Retardancy and Smoke Suppression

“…In this regard, only a few researchers have recently attempted to reduce the amount of smoke generated using FRs composed of biomolecules, instead of a combination of chemical P-FRs and biomolecules. 34 Recent articles on PU foam have focused on the synthesis of FR foam using a one-pot system. 35 However, it is necessary to impart flame retardancy to already produced PU foam for environmental reasons.…”

Polyelectrolyte Coacervate Coatings That Dramatically Improve Oxygen Barrier of Paper

“…Polyelectrolyte deposition is well-known for its ambient processing, and utilization of environmentally benign materials in aqueous-based solutions, to generate functional thin films. − There is little environmental concern in regard to these films due to lack of harmful solvents and materials that are often used to impart barrier properties on cellulosic substrates using more traditional approaches. Furthermore, these coatings are typically ionically cross-linked and can be expected to exhibit recyclable and self-healing behaviors due to the dynamic/reversible nature of ionic bonds. − Coatings prepared with these charged polymers have been utilized for their flame retardant, dielectric, heat shielding, antifouling, and gas barrier properties. − In the present study, the oxygen transmission rate (OTR) of polyethylenimine (PEI)-poly­(acrylic acid) [PAA] coacervates, prepared with and without clay nanoplatelets, on paper substrates is investigated. Each coacervate provides a two-order of magnitude reduction in OTR when compared to the uncoated control (≥96% reduction).…”