▎ 摘　　要

NOVELTY - Preparation method of modified graphene oxide involves (a) pre-dispersing graphene oxide, activator and stabilizer in deionized water, (b) adding coupling agent, dispersant and dispersing additive to modified dispersion of graphene oxide and adding alkali to adjust pH value to be neutral to obtain modified graphene oxide solution, and (c) grinding modified graphene oxide solution into modified graphene layers, ultrasonically filtering and drying to obtain modified graphene powder. USE - Method is useful for preparing modified graphene oxide, which is useful for preparing polystyrene board (claimed). ADVANTAGE - The method ensures simple and economical preparation of modified graphene oxide, and is suitable for industrial production. The modified graphene oxide improves the strength and comprehensive mechanical properties of the polystyrene board, and reduces thermal conductivity coefficient of polystyrene board. DETAILED DESCRIPTION - Preparation method of modified graphene oxide involves (a) pre-dispersing graphene oxide, 2-6 wt.% activator and 2-8 wt.% stabilizer in deionized water, (b) adding 1-5 wt.% coupling agent, 5-10 wt.% dispersant and 0.1-0.5 wt.% dispersing additive to modified dispersion of graphene oxide and adding alkali to adjust pH value to be neutral to obtain modified graphene oxide solution, and (c) grinding modified graphene oxide solution into less than 10 modified graphene layers with a particle diameter D50 of 5-10 mu m and particle diameter D90 of 10-20 mu m, ultrasonically filtering and drying to obtain modified graphene powder. An INDEPENDENT CLAIM is included for preparation method of polystyrene board, which involves adding modified graphene oxide to expanded polystyrene system, carrying out suspension polymerization for 10-12 hours and foaming to obtain foamed polystyrene board, where the expanded polystyrene system comprises pure water, 7-10 wt.% styrene, 0.5 wt.% benzoyl peroxide as initiator, 0.2-0.5 wt.% active calcium phosphate as dispersant and 0.5-1 wt.% pentane as foaming agent, the weight ratio of pure water and styrene is 1-4:1.