Novel flame-retardant thermosets:: Phosphine oxide containing diglycidylether as curing agent of phenolic novolac resins

Phosphorus-containing novolac-epoxy systems were prepared from novolac resins and isobutyl bis(glycidylpropylether) phosphine oxide (IHPOGly) as crosslinking agent. Their curing behavior was studied and the thermal, thermomechanical, and flame-retardant properties of the cured materials were measured. The T-g and decomposition temperatures of the resulting thermosets are moderate and decrease when the phosphorous content increases. Whereas the phosphorous species decrease the thermal stability, at higher temperatures the degradation rates are lower than the degradation rate of the phosphorous-free resin. V-O materials were obtained when the resins were tested for ignition resistance with the UL-94 test. (C) 2004 Wiley Periodicals, Inc.