▎ 摘　　要

NOVELTY - Graphene modified polyethylene terephthalate (PET) film material comprises graphite and ethylene glycol as raw materials, modified graphene prepared by ball milling in supercritical carbon dioxide atmosphere, and then modified graphene is combined with additional terephthalic acid, ethylene glycol is synthesized by in-situ polymerization to obtain graphene-modified PET composite pellets, and graphene-modified PET film material is obtained through multilayer stretch extrusion system. USE - Graphene modified polyethylene terephthalate film material. ADVANTAGE - The graphene-modified polyethylene terephthalate film material helps in improving barrier effect of graphene in PET matrix, and improves overall barrier performance of graphene-modified PET film material. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing graphene-modified PET film material, which involves: (A) adding 1 pts. wt. graphite, more than 10 pts. wt. ethylene glycol, and appropriate amount of catalyst into ball milling tank, then sealing tank with flange screws, and flushing tank with inflatable device to remove carbon dioxide gas from air in tank, then flushing another carbon dioxide gas into tank until pressure reaches 7.3-15 MegaPascal, and closing valve, at same time additional carbon dioxide provided in supercritical state; obtaining modified graphene by ball milling at 32-100 degrees C, and rotating speed of 300-600 rotation/minute for 24-72 hours; (B) adding modified graphene solution infour-necked bottle, heating to 200-265 degrees C under nitrogen protection to react, and refluxing for 1-2 hours to get first solution; taking another appropriate amount of terephthalic acid, and ethylene glycol, then heating up to 200 degrees C under protection of nitrogen to dissolve all terephthalic acid to obtain second solution; adding second solution to first solution, continuing reaction for 2-4 hours, heating up to 270-290 degrees C, and proceeding with polycondensation reaction under vacuum conditions, where reaction completed after 2-4 hours, and protecting under nitrogen; discharging, solidifying, and pelletizing to obtain graphene-modified PET composite pellets; and (C) passing graphene-modified PET composite material pellets through multilayer stretch extrusion system to obtain graphene-modified PET film material.