MODIFIED EXPANDABLE GRAPHITE AND FLAME RETARDANT, PREPARATION METHOD THEREFOR, AND USE THEREOF IN POLYURETHANE FOAM

摘要

The present invention relates to the technical field of flame retardants, specifically relates to a modified expandable graphite and flame retardant, a preparation method therefor and a use thereof in polyurethane foam, and is characterized in that a layer or a plurality of layers of high-polymer surface modifier having special functional groups is adsorbed onto the surface of the expandable graphite. The preparation method for the modified expandable graphite comprises: using an organic modifier containing hydroxyl and a polar hexatomic ring structure to perform surface modification on the expandable graphite; adding a dispersant and mixing uniformly, and then crushing and screening to obtain the modified graphite; and adding the modified graphite in accordance with a certain proportion into polyurethane conjugate polyether, and mixing uniformly so that the modified graphite can be dispersed and suspended uniformly in the polyether. The flame retardant property of the obtained polyurethane thermal insulation material is improved greatly without affecting other properties of rigid polyurethane foam, has an excellent flame retardant property, a longer-lasting flame retardant effect, a greatly improved oxygen index, a slashed peak value of thermal release rate and so on.