PLA/PBAT film, preparation method and application

Abstract

The invention belongs to the technical field of high polymer material preparation and particularly discloses a PLA / PBAT film, a preparation method and application. The method comprises the following steps that PLA, PBAT resin and an auxiliary agent are mixed; then extrusion granulation is carried out through a double-screw extruder; melt extrusion is carried out through a single-screw film castingmachine after extrusion granulation, and a casting sheet on a casting roller; and then the rotation speeds of a fixed roller and a movable roller are adjusted to carry out longitudinal stretching inorder to obtain the uniaxially longitudinally stretched PLA / PBAT film. According to the method, oriented crystallization is induced through stretching at a certain temperature, the crystallinity of the film is greatly improved, and the PLA / PBAT film has high tensile strength and elongation at break in the stretching direction. No nucleating agent or other assistants are added in the technology, the influence on the transparency of the film is avoided, the prepared film has complete biodegradability, the preparation technology is continuous, simple, safe and environment-friendly, and the film can be widely applied to the fields of packaging and the like.

Description

technical field [0001] The invention belongs to the technical field of polymer material preparation, and in particular relates to a PLA / PBAT film, a preparation method and an application. Background technique [0002] Polylactic acid (PLA) is a relatively mature biodegradable resin at present. It has the characteristics of transparency, easy processing and complete biodegradation, and its synthetic raw materials are derived from natural materials. It is an ideal material to replace petroleum-based resins such as polyethylene. As a substitute for polyethylene to prepare plastic wrap, packaging film and agricultural film, PLA has high tensile strength, but poor impact strength and tear resistance, slow crystallization rate, low crystallinity, low heat distortion temperature, and it is difficult to reach polyethylene film. The technical performance index of polyadipate / butylene terephthalate (PBAT) has good flexibility and film-forming properties, high thermal stability, and is...

AI Technical Summary

Problems solved by technology

[0003]However, adding a small amount of PBAT to PLA can improve the elongation at break of PLA to some extent, but will reduce the tensile strength and modulus of PLA

When the amount of PBAT added is 20% to 50%, PLA and PBAT are almost incompatible, and the defects in crystallinity and compatibility of the two substances lead to poor mechanical properties of the blend

[0004] While improving the toughness of PLA / PBAT blends, without reducing its tensile strength, at the same time increasing the crystallization rate and crystallinity of PLA, and preparing PLA with excellent degradability Transparent PLA / PBAT films still lack effective technical means

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