Two-Dimensional Nanomaterials as Smart Flame Retardants for Polyurethane
Emad S. Goda, Mahmoud H. Abu Elella, Heba Gamal, Sang Eun Hong, Kuk Ro Yoon
Abstract
Polyurethanes (PUs) are multilateral polymeric materials utilized widely for various industrial purposes. However, these polymers have the drawbacks of poor thermal stability, high combustion behavior, and emission of toxic gases and smoke. This is because of their characteristic cellular morphology, porosity, and aliphatic segments restricting further applications. Consequently, the research on improving the flammability of polymers is of great concern. In particular, halogen-based flame retardants (FRs) demonstrate effective behavior against fire growth, but they are restricted because of their apparent toxicity. Product specifications such as mechanical properties, durability, and suitable safeness are greatly needed for applications in the market. There is therefore an urgent need to develop new-generation FRs for PU. The usage of 2D nanomaterial FR fillers has been broadly expanded for polymers—especially PUs—because of their outstanding features such as high thermal stability, lower thermal conductivity, and ability to form a strong carbonaceous layer on the polymer. Also, 2D materials can largely boost the mechanical properties of polymers. Commonly, 2D nanomaterials can retard flames in the condensed phase by creating an insulating barrier for suppressing smoke density and heat transfer. In this chapter, the authors conduct an overview of the current research performed on utilizing 2D material FRs for PU and the related mechanism for the retardation of fire growth.