▎ 摘　　要

NOVELTY - Fully biodegradable high-barrier composite packaging film includes 20-30 pts. wt. polylactic acid, 70-80 pts. wt. polybutylene adipate terephthalate, 0.2-0.5 pts. wt. chain extender, 0.5-1 pts. wt. plasticizer, 3-5 pts. wt. modified nano silica and 1-3 pts. wt. modified graphene. USE - Fully biodegradable high-barrier composite packaging film. ADVANTAGE - The fully biodegradable high-barrier composite packaging film has greatly improved oxygen barrier performance, and improved water vapor barrier performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing fully biodegradable high-barrier composite packaging film, which involves: (A) placing polylactic acid and polybutylene adipate terephthalate at 80 degrees C for 4 hours; (B) mixing epoxy chain extender, plasticizer and polylactic acid uniformly; (C) passing the twin-screw extruder granulator to repeat the granulation twice to obtain polylactic acid masterbatch; (D) mixing polybutylene adipate terephthalate with polylactic acid masterbatch, modified nano silica, and modified graphene uniformly; and (E) repeating the granulation three times through the twin-screw extruder granulator to obtain the blown film mechanism produces nano-particle modified nano-particle modified high-barrier composite packaging film.