▎ 摘　　要

NOVELTY - Non-adhesive and high-viscosity door panel protective film comprises outer film composed polymethyl methacrylate, thermoplastic elastomer, polyvinylidene fluoride, perfluorosulfonic acid resin fiber, sulfonated graphene and compatibilizer; a middle film composed of low density polyethylene and linear low-density polyethylene; and an inner film composed of low density polyethylene, linear low-density polyethylene, butyl chitosan, and nano cellulose whisker. USE - The non-adhesive and high-viscosity door panel protective film is useful in field of polymer material. ADVANTAGE - The protective film has high viscosity, strong adhesion, good adhesion to the door panel, simple preparation process, and wide application prospects. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for: a method for preparing protective film, comprising (i) adding polymethyl methacrylate, thermoplastic elastomer, polyvinylidene fluoride, perfluorosulfonic acid resin fiber, sulfonated graphene, and compatibilizer into a high-speed mixer and uniformly stirring and mixing, transferring to double melt extrusion granulation in the screw extruder to obtain the outer film material; (ii) adding low density polyethylene and linear low-density polyethylene into a high-speed mixer and uniformly mixing, transferring to twin-screw extruder for melt extrusion and granulation to obtain the intermediate film material; (iii) adding low density polyethylene linear low-density polyethylene, butyl chitosan, and nano cellulose whiskers into a high-speed mixer and uniformly mixing, and transferring to a twin-screw extruder to melt, extrude, and granulate to obtain the inner film material; (iv) adding the outer film material, middle film material, and inner film material into the outer film hopper, middle film hopper, and inner film hopper respectively, and extruding each hopper by a three-layer co-extrusion film blowing machine, where the screw temperature of the outer film extrusion mechanism during the extrusion process is 230-250 degrees C, the rotating speed is 320-360 revolutions/minute, and the screw temperature of the middle-layer film extrusion mechanism is 180-210 degrees C, the speed is 320-360 revolutions/minute, the screw temperature of the inner film extrusion mechanism is 200-210 degrees C, the speed is 320-360 revolutions/minute, converge to spiral blown film die head, die head temperature is 230-250 degrees C, extruding by die head, stretching, air-cooling at 5-8 degrees C and shaping, performing corona treatment on one side of the inner film under current intensity of 5-8 A for 0.5-1 seconds, cutting the edges and rewinding. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the non-adhesive and high-viscosity door panel protective film useful in field of polymer material.