▎ 摘　　要

NOVELTY - Preparation of waterproof coating comprises adding hydroxyl terminated polylactic acid with molecular weight of 500 to tetrahydrofuran, heating at 100?oC, adding dibenzoyl peroxide and nano graphene oxide to obtain graphene grafted polylactic acid, dehydrating polytetramethylene ether glycol, adding catalyst and isophorone diisocyanate for nucleophilic addition reaction to obtain polyurethane prepolymer, mixing graphene grafted polylactic acid and polyurethane prepolymer to obtain polyurethane composite emulsion, adding triethylamine into polyurethane composite emulsion which is embedded in polylactic acid, adding talcum powder prepared by talcum powder preparation device, adding triethylamine and neutralizing reaction. USE - The method is used for preparation of waterproof coating. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for talc powder preparation device comprising fixed connection frame, friction chamber, centrifugal hole and crushing member.