Modified magnesium hydroxide flame retardant, epoxy resin composite material and preparation method

The invention relates to a modified magnesium hydroxide flame retardant, an epoxy resin composite material and a preparation method. The representative formula of the modified magnesium hydroxide flame retardant is MH (at) PPAC, MH represents magnesium hydroxide, PPAC represents 2-(diphenylphosphino) benzoic acid, and MH (at) PPAC represents 2-(diphenylphosphino) benzoic acid modified magnesium hydroxide. The epoxy resin composite material is obtained by carrying out curing reaction on a mixture of the modified magnesium hydroxide flame retardant, epoxy resin and DDM. The modified magnesium hydroxide flame retardant has high dispersity and flame retardance, compared with a traditional alkali precipitation method, preparation conditions are easy to control, the preparation technological process is short, input equipment is few, magnesium hydroxide is wide in source, raw materials are easy to obtain, waste gas is not generated in the process of preparing flame-retardant magnesium hydroxide, and the flame-retard