Green, tough and highly efficient flame-retardant rigid polyurethane foam enabled by double network hydrogel coatings
Yubin Huang, Jinming Zhou, Ping Sun, Lei Zhang, Xiaodong Qian, Saihua Jiang, Congling Shi
Abstract
a facile casting and curing process. This strategy can create a homogeneous hydrogel fire-resistant layer with strong adhesion on the outermost surface of the substrate. Due to good water holding capacity and excellent thermal management properties, the hydrogel coating showed excellent fire retardancy. As a proof-of-concept, polyacrylic-polydopamine (PAAm-PDA) double network hydrogel coating was applied to an extremely flammable RPUF substrate. Compared with the neat foam, the PAAm-PDA coated RPUF exhibited an overall improvement in fire-safety performance, including a rapid self-quenching behavior, a six-fold enhancement in time to ignition (TTI), and 39.7% and 42.2% decreases in the mean heat release rate (HRR) and total smoke production (TSP), respectively. Furthermore, the tough hydrogel-coated RPUF possessed enough mechanical properties to meet the requirement of its practical applications. Benefiting from its low cost, easy-to-process and eco-friendly characteristics, this hydrogel fireproof coating strategy provides a new direction for developing green and safe structural materials with widespread use.