Polylactic acid packaging film with controlled-release antioxidant activity and preparation method thereof

The invention discloses a polylactic acid packaging film with controlled-release antioxidant activity. The polylactic acid packaging film comprises the following components in percentage by mass: 80-98% of matrix resin and 2-20% of natural antioxidant-loaded multi-walled carbon nanotube particles. The polylactic acid packaging film is prepared by loading a natural antioxidant onto a multi-walled carbon nanotube, then mixing the natural antioxidant-loaded multi-walled carbon nanotube with the matrix resin, and carrying out extrusion by adopting a melt extrusion method, wherein the matrix resinis a blend of polylactic acid and poly trimethylene carbonate. According to the invention, raw materials used in a preparation method can be biodegraded, and production process is simple; the multi-walled carbon nanotube is used for loading the natural antioxidant, and slow release of the natural antioxidant can be effectively controlled, so the timeliness of the antioxidant effect of the packaging film is improved; and t