Preparation method for degradable plastic composite film with oxygen separation performance

Abstract

The invention discloses a preparation method for a degradable plastic composite film with an oxygen separation performance. In the preparation method, degradable plastic master batch PBM mature in the present market, Pullulan polysaccharide and film-level LDPE are employed as raw material with addition of anti-oxidants and ultraviolet ray absorbers, tannic acid is employed for modifying Pullulan polysaccharide, further the plastic film three-layer co-extrusion film blowing technology is employed, and a three-layer plastic composite film with good oxygen separation performance, degradability and mechanical properties is prepared. The inner layer, the middle layer and the outer layer of the composite film are LDPE / PBM / Pullulan, PBM / Pullulan and LDPE / PBM / Pullulan respectively. The composite film can decompose automatically under action of oxygen enrichment and microbes, a wasted film can be degraded and digested completely by microbes in nature, the oxygen separation performance of the composite film can be raised by 70%-80% compared with the oxygen separation performance of an LDPE film with the same thickness, and the mechanical properties of the composite film are almost the same as mechanical properties of an LDPE film with the same thickness. The composite film is advantaged by simple production technology, high production efficiency and easy industrial enforcement.

Description

technical field [0001] The invention belongs to the field of plastic film materials, in particular to a preparation method of a degradable plastic composite film with oxygen barrier properties. Background technique [0002] The preservation of food and medicine requires packaging materials to have excellent oxygen barrier properties to prevent the oxygen in the air from destroying their components. For the packaging of foods and medicines that require high oxygen barrier properties, traditional plastic packaging film materials have different degrees of air permeability, which seriously affects the quality of packaging. At present, traditional packaging materials such as glass and aluminum foil are still the main packaging materials for oxygen barrier substances, or these materials are used in combination with polymer materials. This makes the packaging cost high, difficult to recycle materials, and pollutes the environment. Therefore, the development of new cheap, environm...

AI Technical Summary

Problems solved by technology

However, further studies have found that although the oxygen barrier and degradability of the oxygen barrier and degradable plastic film are greatly improved compared with LDPE films, from the perspective of application, the oxygen barrier and degradability still need to be further improved

In the LDPE / PBM / Pullulan system, increasing the content of PB and Pullulan, especially the increase of the content of Pullulan, can improve the oxygen barrier and degradability, but the overall mechanical properties of the film are reduced, and the application is greatly restricted.