Flame-retardant epoxy resins: An approach from organic-inorganic hybrid nanocomposites

Abstract

Phosphorus-containing epoxy-based epoxy–silica hybrid materials with a nanostructure were obtained from bis(3-glycidyloxy)phenylphosphine oxide, diaminodiphenylmethane, and tetraethoxysilane in the presence of the catalyst p-toluenesulfonic acid via an in situ sol–gel process. The silica formed on a nanometer scale in the epoxy resin was characterized with Fourier transform infrared, NMR, and scanning electron microscopy. The glass-transition temperatures of the hybrid epoxy resins increased with the silica content. The nanometer-scale silica showed an enhancement effect of improving the flame-retardant properties of the epoxy resins. The phosphorus–silica synergistic effect on the limited oxygen index (LOI) enhancement was also observed with a high LOI value of 44.5. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 986–996, 2001