▎ 摘　　要

NOVELTY - Functionalized graphene derivatives (I)-(IV) are new. USE - Functionalized graphene derivatives used for preparing crosslinkable polyurethane rigid foam (claimed). ADVANTAGE - The foam has density of 36-55 kg/m3, compressive strength of 1232-1730 kPa, porosity of 84-92%, vertical flame (UL-94) rating of 0, limit oxygen index of 23.4-34.5%, and thermal conductivity of 0.028-0.035 W/(m.K). The polyurethane foam has flame retardant property, improved flame retardancy and compression, and simple preparation. DETAILED DESCRIPTION - Functionalized graphene derivatives of formulae (I)-(IV) are new. X=epoxy; Y'=graphene; and Z=1-6C alkyl. INDEPENDENT CLAIMS are included for: (1) preparation of compounds (I)-(IV); and (2) preparation of crosslinkable polyurethane rigid foam comprising taking polyisocyanate, polyol, catalyst, and blowing agent, mixing, and adding 10-60 pts. wt. functionalized graphene.