Barrier degradable antibacterial food fresh-keeping film, and preparation method and application thereof

Abstract

The invention provides a barrier degradable antibacterial food fresh-keeping film and a preparation method thereof. The preparation method comprises the following steps: drying polylactic acid and anantibacterial nanomaterial, weighing the polylactic acid, the antibacterial nanomaterial, a plasticizer, an antioxidant and a chain extender, and carrying out extrusion granulation on the obtained mixture to obtain modified polylactic acid resin particles; and adding the modified polylactic acid resin particles into a casting machine, extruding the particles to form a casting sheet, and carrying out bidirectional stretching. The barrier degradable antibacterial food fresh-keeping film keeps the performances of a basic film, has excellent antibacterial activity and heat resistance and a high barrier function, can be applied to packaging materials, can replace functional packaging materials such as PVDC, PA and EVOH aluminum-platinum materials, can be completely biodegraded when applied inorder to prevent environmental pollution, can be completely comparable with petroleum-based products in cost performance, and can be widely applied to the fields of precision electronic devices, automobile mechanical parts, foods, medical products and the like.

Description

technical field [0001] The invention relates to the technical field of packaging materials, in particular to a preparation method of a barrier degradable antibacterial food fresh-keeping film. Background technique [0002] Polylactic acid is a degradable bio-based polymer, which is derived from renewable natural resources. It uses lactic acid obtained by fermentation of corn or potato starch as the basic raw material, and is developed by polycondensation reaction or its dimer lactide. It is prepared by cyclic polymerization, and can be biodegraded in nature to generate carbon dioxide and water, which is environmentally friendly. It has completely biodegradable properties, good biocompatibility, good physical and mechanical properties and processing properties. It is suitable for processing injection molding products, foam materials, films, fibers, etc., and is mainly used in the fields of biomedicine and food packaging. Under the current concept of promoting energy saving, ...

AI Technical Summary

Problems solved by technology

Patent CN101676324 discloses a polypropylene biaxially oriented film (BOPP) pearlescent synthetic paper masterbatch, which can be used as a packaging material for candy, ice cream, etc., but its matrix is ​​polypropylene. Although it is more environmentally friendly, its source is mostly petroleum In terms of chemical industry, the dwindling and shortage of petroleum resources is not conducive to its sustainable development

And although this method adopts the method of side feeding in order to solve the processing difficulties, the side feeding system has relatively high requirements for processing equipment

Patent CN110003753 discloses a high-barrier coating for biaxially stretched polyester film and its preparation method. This method prepares a film with high barrier performance by coating a barrier coating, and the operation is more complicated.

Patent CN105622974 discloses a high-barrier and high-transparency PET composite film and its preparation method. The boron nitride nanosheets contained in the film make the film have a certain high barrier performance, but the coating method used also has certain complicated operations. , and the process conditions are relatively high

[0004] Chinese patent 201310213828.0, published on September 25, 2013, the patent name of the invention is "a biaxially stretched polylactic acid / graphene composite film". / Graphene composite film, the above patents all use biaxial stretching process to effectively improve the mechanical properties and temperature resistance of polylactic acid film or polylactic acid composite film, but the biaxial stretching process does not change the structure of the material, forming a porous Fiber membrane structure, no antibacterial, improved barrier properties and other properties

[0005] Chinese patent (103950257A) discloses a high-barrier bio-based composite film, the latest composite film uses polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene succinate (PBS) biomaterials, but Its barrier layer is polyvinylidene chloride (PVDC), ethylene vinyl alcohol copolymer (EVOH) and other resins of the hydroxyl group. They are not bio-based materials, and they do not degrade and are not environmentally friendly.

Images