Multi-layer co-extrusion based biodegradable mulch film and preparation method thereof

Abstract

The invention belongs to the technical field of agricultural films and discloses a multi-layer co-extrusion based biodegradable mulch film and a preparation method thereof. The mulch film adopts a two-layer or three-layer structure, wherein an upper surface layer contains 99wt%-99.9wt% of biodegradable resin A and 0.1wt%-1wt% of auxiliaries; a middle layer is the biodegradable resin A; a lower surface layer contains 70wt%-97wt% of the biodegradable resin A and 3wt%-30wt% of biodegradable herbicide master batches; preparation of the master batches comprises steps as follows: 10wt%-60wt% of herbicide is mixed with 0.5wt%-7wt% of a surfactant A with a hydrophilic-lipophilic balance value being 7-10, and an obtained mixture is subjected to ultrasonic activation; an obtained product is mixed with 25wt%-75wt% of biodegradable resin B and 1wt%-10wt% of a surfactant B with a hydrophilic-lipophilic balance value being 3-6 at a high speed, an obtained mixture is subjected to extrusion pelletization, and the herbicide master batches are obtained. A mass ratio of the surfactant A to the surfactant B is 1:1-1:2.

Description

technical field

[0001] The invention belongs to the technical field of agricultural films, in particular to a multi-layer co-extruded biodegradable film and a preparation method thereof. Background technique

[0002] Weed-killing mulch is a functional mulch product with weed-killing effect prepared by adding herbicides to plastic films. During the use of the mulch film, the herbicide diffuses to the surface of the mulch film to form a herbicidal molecular layer, which dissolves and drips to the ground together with the water droplets attached to the surface of the mulch film, and is absorbed by the soil to form a herbicide treatment layer with a certain concentration, which finally achieves the purpose of inhibiting the growth of weeds, And the purpose of causing weed death. Biodegradable weed-killing mulch film is prepared by mixing herbicide or herbicide masterbatch with fully biodegradable polymer resin with fully biodegradable polymer resin as the carrier. It has the fu...