The invention discloses a paper-based
composite film, which adopts a four-layer structural design, and the outer layer is an
ultraviolet shielding layer formed by
coating TiO2 with
lignin; the
transition layer is composed of 32-64 PLA / PBAT alternating microlayers, and the multiple alternating transition
layers form a zigzag
gas barrier path; ag-coated ZIF-8 nanoparticles are loaded on the paper base layer, so that long-acting
antibiosis is realized by slowly releasing silver ions; and the inner layer adopts a PPC / PBS blend to support the heat sealing layer with adjustable heat sealing strength. According to the preparation process, a gradient micro-layer structure is constructed through a multi-runner co-
extrusion die head and a layer multiplier, silver ions are loaded to ZIF-8 through an ultrasonic-vacuum impregnation process, the hydroxyl density of the surface of the paper base layer is improved through
plasma treatment, good interlayer strength is achieved,
ester bond crosslinking is induced in a pre-
irradiation mode, and the product is prepared. The paper-based
composite film has
ultraviolet shielding, gradient blocking, slow-release antibacterial and controllable heat sealing performance, the
interface bonding strength of a traditional paper-based
composite film is greatly improved, all components are biodegradable, and the paper-based composite film is suitable for packaging of food,
medicine and the like.