Recent Development on Flame Retardants for Polyurethanes

Flame retardants are compounds that prevent fire and are being used in various materials to reduce flammability. This chapter describes, in detail, the main ideas that have provided effective ways to provide flame retardancy for polyurethanes and other polymers. The synthetic routes, design of procedures, and possible variations are discussed to serve as guidelines and to help brainstorm for new methodologies and future projects. The combination of different flame retardants to create a synergetic effect is an extremely important aspect of this field, and this plays a key role in delivering effective results. The chapter begins with a discussion into the conceptual framework of additive and reactive flame retardants, their respective advantages, and challenges encountered. Widely known flame retardants—based on halogen, carbon, metal oxides, nitrogen, phosphorus, and nanoparticles—are discussed regarding their respective mechanisms. The chapter also discusses how they can be used to simultaneously reduce flammability and improve properties such as mechanical strength and environmental stability.