Hybrid strategies for improving the fire performance of epoxy resin cured with aliphatic hardener

The use of aliphatic amines as hardeners is preferable over the toxic aromatic amines, however, their incorporation increases the flammability of the resin. This presentation will summarize different hybrid strategies which we have recently developed to flame retard bisphenol A diglycidyl ether (DGEBA) resin cured with a cycloaliphatic amine. The synthesis of in-situ sol-gel silica nanoparticles in the epoxy resin followed by incorporation of two DOPO based flame retardants in combination with other synergists or the use of humic acid and ammonium polyphosphate, could help achieve non-dripping V0 classification in UL 94 tests with low phosphorous loadings (e.g. 1, 2 wt%). The formation of a hybrid silica-epoxy network guarantees a better dispersion of more polar additives in the hydrophobic resin, leading to tailored interphases. These strategies enable to boost the flame retardancy of the matrix, without compromise in mechanical and thermal properties of the composites.