Flame-retardant epoxy thermosets derived from renewable resources: Research development and future perspectives

Nowadays, the predominant source for approximately 90% of epoxy resin materials worldwide is the diglycidyl ether of bisphenol A (DGEBA). However, the increasing recognition of environmental concerns, such as global warming and the depletion of petroleum reserves, necessitates the exploration of alternative options, specifically bio-epoxy resin derived from sustainable resources. Nonetheless, the inadequate flame retardancy of bio-epoxy resin presents a notable drawback, limiting its applicability in high-risk environments. The objective of this review article is to provide a concise overview of the latest and up-to-date advances in flame-retardant epoxy resins derived from sustainable sources. Firstly, the discussion encompasses inherently flame-retardant bio-based epoxy resins, considering both bio-based epoxy monomers and bio-based curing agents, focusing on their flame retardancy and mechanical properties. Furthermore, the utilization of phosphorus-containing and silicon-containing additives in bio-based epoxy is explored. Additionally, a comprehensive evaluation of partially bio-based intrinsically flame retardant epoxy resins is provided. Finally, this article offers an extensive survey of the current state-of-the-art in the field and presents future perspectives, serving as a valuable resource for researchers engaged in the study of flame-retardant epoxy resins derived from sustainable resources.