Phosphorus-containing flame retardant epoxy thermosets: Recent advances and future perspectives

Their pervasive use in industrial applications renders the development of environmentally benign flameretardant epoxy (EP) thermosets a timely and important goal. The last two decades have witnessed the rise of phosphorus (P)-containing flame retardants for EP due to their high flame retardancy efficiency, low toxicity, multiple modes of action, molecular diversity and other favorable properties. P-containing flame retardants are classified into two types: reactive and additive, according to whether they participate in the curing process. Recent advances in both of these classes of P-containing flame retardants motivate this comprehensive review on the design and synthesis of P-containing flame retardants and their impact on the material properties of EP thermosets. This review focuses on the state-of-the-art knowledge of P-containing flame retardants and their effects on flame retardancy, thermal stability and mechanical properties of the resultant EP. First, representative flame-retardant mechanisms are reviewed. Subsequently, practical applications of P-containing flame-retardant EP thermosets are presented. Finally, the key challenges associated with P-containing flame retardants for EP thermosets are highlighted, and opportunities for future research in the field are proposed. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Phosphorus (P)-containing flame retardants have been widely used in epoxy thermosets due to their high flame retardancy efficiency, low toxicity, and impact on material properties. They are classified into reactive and additive types, and have potential for future research and development.