Preparation of mesoporous zinc ferrite flame retardant with different scales and its performance in epoxy resin

Multiple-scale mesoporous zinc ferrite (ZF) nanoparticles were prepared by controlling the calcination temperature and used in epoxy resin (ER). The scale effect of ZF nanoparticles on thermal stability, flame retardancy, and mechanical properties of ER composites was studied in detail. Results showed that ZF nanoparticles at all scales could improve the flame-retardant performance of ER. In particular, the 400-ZF nanoparticles show the best performance. When 5 phr of 400-ZF nanoparticles were added to the ER matrix, the peak heat release rate, peak smoke release, and peak carbon monoxide production of the ER were reduced by 38.3%, 36.3%, and 50.0%, respectively. In addition, the 400-ZF nanoparticles decreased the thermal stability and mechanical properties of ER slightly. These properties are attributed to its suitable crystal size and specific surface area. This flame-retardant system provided the possibility of the relationship between particle size and specific surface area, catalytic carbonization, and flame-retardant performance. • Multiple-scale zinc ferrite was prepared by controlling the calcination temperature. • The scale effect of Zinc ferrite nanoparticles on flame retardancy of ER was studied. • The 400-ZF has the best char-forming ability and flame retardancy in the ER matrix. • Excellent properties are attributed to suitable crystal size and specific surface area.