Thermal degradation and fire resistance of epoxy-amine-phenolic blends

The effects of the addition of different epoxy resins on the thermal stabil ity of phenolic resolees are reported. Blends of phenolic resins with diffe rent compositions of epoxy resins, cured with amine hardeners, were charact erized by thermal gravimetric analysis and cone calorimetry to determine th eir thermal stability and fire resistance. The thermal degradation of pheno lic resolees is characterized by a complex mechanism with at least two diff erent processes which lead to the production of a stable and resistant char structure. On the other hand, the epoxy resins studied, either aliphatic o r aromatic, degrade in a single step. The results demonstrate that the epox y-amine content should be kept under 15 wt.% to avoid a significant reducti on of the thermal stability of the blend. However, blending with epoxy-amin es is a suitable route to improve the mechanical properties of phenolic res ins or to reduce the cure temperature. (C) 2001 Elsevier Science Ltd. All r ights reserved.