Preparation method of biodegradable composite film

Abstract

The invention discloses a preparation method of a biodegradable composite film. The preparation method comprises the following steps: S1, mechanically mixing polylactic acid, poly (butylene adipate-co-terephthalate) and modified starch, and stirring at a constant speed to form a premix; s2, adding the premix obtained in the step S1 from a charging hole of a double-screw extruder, and carrying out melt extrusion, water cooling and granulation by a granulator; s3, drying the material obtained in the S2 in an air dry oven to obtain the special resin for film blowing; the biodegradable composite film prepared through a melt blending extrusion and film blowing technology has the advantages of degradability, environmental friendliness and the like, meanwhile, the brittleness of the polylactic acid is improved through the poly (butylene adipate-co-terephthalate), and the poly (butylene adipate-co-terephthalate) and the polylactic acid are biodegradable materials and meet the environmental protection requirement; the defect of serious brittleness of a polylactic acid film is overcome, the biodegradable composite film is prepared through a solution tape casting method, and the problem that hydrophilic starch is incompatible with hydrophobic polylactic acid is solved.

Description

technical field [0001] The invention relates to the technical field of film preparation, in particular to a preparation method of a biodegradable composite film. Background technique [0002] According to statistics, in 2014 the world produced 311 million tons of plastics, which is expected to triple by 2050, accounting for 20% of the world's annual oil consumption. The production of these traditional petrochemical plastics consumes a lot of fossil fuels, and will release hundreds of millions of tons of CO into the atmosphere, which is one of the main factors for excessive carbon emissions. After a short period of use, it will be discarded in large quantities, and improper waste disposal It has caused unhealthy living conditions, degraded the quality of plastic polluted rivers and marine groundwater, and caused endless "white pollution". [0003] In recent years, with the rapid development of social economy, the widespread use of polymer materials, especially plastic films,...

AI Technical Summary

Problems solved by technology

The production of these traditional petrochemical plastics consumes a lot of fossil fuels, and will release hundreds of millions of tons of CO into the atmosphere, which is one of the main factors for excessive carbon emissions. After a short period of use, it will be discarded in large quantities, and improper waste disposal It has caused unhealthy living conditions, made plastic polluted rivers and marine groundwater quality worse, and caused endless disasters of "white pollution"