Although lightweight polymeric foams work well for thermal insulation, they tend to be flammable and do not bond well with most fire-retardant coatings. Drawing inspiration from the adhesion capabilities of snails and tree frogs, Ma et al. designed a polymeric coating based on a copolymer of hydroxyethyl acrylate (HEA) and sodium vinylsulfonate (VS). This waterborne, phase-separated polymer can be sprayed onto foams, where the hydroxyl groups in the HEA lead to strong H-bonding and the sodium sulfonate groups in the VS provide fire retardancy. The coating does not affect the thermal insulation properties of the foam but can self-extinguish a flame with low heat and smoke release because of its tendency to char.
ACS Nano 10.1021/acsnano.1c02254 (2021).