The present invention discloses a preparation method of a flame-retardant polylactic acid-based composite material. A free radical initiator and a modified phosphorus-containing flame retardant are added into a biodegradable polylactic acid resin matrix, blended and granulated in a twin-screw extruder to prepare a resin masterbatch, and the resin particles are dried and injection-molded by an injection molding machine to obtain a polylactic acid composite material. Through reasonable formula design, the present invention blends the above modified phosphorus flame retardant, free radical initiator and polylactic acid molecules, and directly prepares a phosphorus flame-retardant polylactic acid through melt blending under the action of a peroxide free radical initiator. The present invention utilizes maleic anhydride grafting reaction to graft phosphorus-based small molecules onto polymer molecular chains in the form of covalent bonds through extrusion via condensation reaction of acid anhydride and polar groups. The prepared phosphorus-based flame-retardant polylactic acid composite material has excellent performance, can upgrade the flame retardant grade of the polylactic acid composite material to UL94 V-0 level with a low addition amount, and has a limiting oxygen index of 31.6%.
Country Code: CN
Application Number: CN202410558019.1
