▎ 摘　　要

NOVELTY - The preparation of modified graphene involves pre-dispersing redox graphene powder and activator in deionized water or an organic solvent, adding modifier and active dispersant, carrying out dispersion modification of graphene by dispersant, filtering and drying after modification to obtain modified graphene powder. The addition amount of graphene is 5-20 wt.% of deionized water or organic solvent. The addition amount of activator is 1-5 wt.% of graphene. The addition amount of modifier is 1-5 wt.% of graphene. USE - Preparation of modified graphene used in expandable polystyrene molded polystyrene board (claimed). ADVANTAGE - The method enables preparation of modified graphene with high strength, low thermal conductivity, and excellent mechanical properties at low cost by simple and environmentally-friendly process. DETAILED DESCRIPTION - The preparation of modified graphene involves pre-dispersing redox graphene powder and activator in deionized water or an organic solvent, adding modifier and active dispersant, carrying out dispersion modification of graphene by dispersant, filtering and drying after modification to obtain modified graphene powder. The addition amount of graphene is 5-20 wt.% of deionized water or organic solvent. The addition amount of activator is 1-5 wt.% of graphene. The addition amount of modifier is 1-5 wt.% of graphene. The addition amount of active dispersant is 3-10 wt.% of graphene. The addition amount of dispersant is 0.5-1 wt.% of graphene. An INDEPENDENT CLAIM is included for usage of modified graphene, which involves adding modified graphene to white material expandable polystyrene system for suspension polymerization, foaming to obtain expandable polystyrene molded polystyrene board. The white material expandable polystyrene polymerization system comprises pure water, styrene, initiator benzoyl peroxide, dispersant active calcium phosphate, and foaming agent pentane. The weight ratio of pure water to styrene is (1-4):1. The addition amount of graphene is 0.5 wt.% of styrene. The addition amount of initiator is 0.2-0.5 wt.% of styrene. The addition amount of dispersant is 0.5-1 wt.% of styrene. The foaming agent pentane is 7-10 wt.% of styrene.