Progress on Intrinsically Flame-retardant Bio-based Epoxy Thermosets

Currently, most epoxy thermosets especially diglycidyl ether of bisphenol A (DGEBA) -type epoxy monomers are sourced from petroleum resources. Due to the restrictions on greenhouse gas emissions, the development of bio-based epoxy thermosets to replace petroleum-based epoxy thermosets has received more and more attention. However, like petroleum-based counterparts, bio-based epoxy thermosets are highly flammable. Therefore, the development of intrinsically flame-retardant bio-based epoxy thermosets is extremely important. The future development direction of intrinsically flame-retardant bio-based epoxy thermosets must be green and sustainable. At present, intrinsically flame-retardant bio-based epoxy thermosets still have some defects such as poor thermal stability, and there is a long way to go. Considering the development trend in this field, increasing the functionality of bio-based epoxy monomers or curing agents, improving biomass content and biodegradability are several key factors for the future development of flame-retardant bio-based epoxy thermosets with high-performance. This review mainly discusses the recent progress and prospects of the preparation of intrinsically flame-retardant bio-based epoxy thermosets from bio-based resources. The mechanical properties, thermal stability and flame retardancy of partly bio-based intrinsically flame-retardant epoxy thermosets from either bio-based epoxy monomers or bio-based curing agents are emphatically introduced. In addition, the fully bio-based flame-retardant epoxy thermosets are also introduced. Finally, the opportunities and challenges of the future development of the intrinsically flame-retardant bio-based epoxy thermosets have been briefly prospected. [GRAPHICS] .