Preparation method of high-transparency easy-to-tear polylactic acid blown film

Abstract

The invention provides a preparation method of a high-transparency easy-to-tear polylactic acid blow-molded film. The high-transparency easy-to-tear polylactic acid blow-molded film is composed of a mixture of polylactic acid (PLA), polyterephthalic acid-adipic acid-butanediol ester (PBAT), a plasticizer acetyl tributyl citrate, a lubricant ethylene bisstearamide, an opening agent erucyl amide anda nucleating agent white carbon black. The preparation method comprises the following steps: weighing PLA, PBAT, a plasticizer, a lubricant, an opening agent and a nucleating agent in proportion, adding into a mixer, uniformly mixing, adding from a feeding hole of a double-screw extruder, carrying out melt extrusion, water cooling, pelletizing and drying to obtain special modified polylactic acidfilm-blowing resin, and carrying out water cooling blow molding film formation by a film blowing machine through a down-blowing method to obtain the high-transparency easily-torn polylactic acid blow-molded film. According to the invention, the PBAT, the plasticizer, the lubricant, the opening agent and the nucleating agent have a synergistic effect, so that the tensile elongation at break of thepolylactic acid film can be effectively improved, the polylactic acid film has high transparency, the flat wrinkle-free easy-to-tear high-transparency complete biodegradable film is obtained, the tensile strength is as high as 54.6 MPa, and when the thickness of the film is 0.025 mm, the light transmittance reaches 94% or above and the haze reaches 5.3%; and the film has good mechanical properties and excellent transparency, and can replace PE, PP, PVC and other films.

Description

technical field [0001] The invention belongs to the field of polymer materials, and relates to a preparation method of a highly transparent and easy-to-tear polylactic acid blown film. Background technique [0002] Unlike traditional petroleum-based plastics, polylactic acid is polymerized from lactic acid fermented from plant starch. This is a renewable resource and has biodegradable properties, which is of great significance to protecting the environment. In the situation of increasingly tense oil energy, the development and research of polylactic acid resin is particularly important. The properties of polylactic acid itself are similar to the general-purpose plastic polypropylene, such as high modulus, high tensile strength and good processability. However, the brittleness of polylactic acid is serious, and the impact strength is less than 5KJ / m 2 , seriously restricting its wide application. [0003] Common applications of film packaging materials include food packagi...

AI Technical Summary

Problems solved by technology

[0009] The above studies on the modification of polylactic acid blown film at home and abroad all adopt the method of blowing up and blowing cold film, but the serious brittleness, non-tear resistance and poor flexibility of pure polylactic acid film are the main factors affecting the wide application of polylactic acid blown film. question

But all do not see the report that adopts the method for blowing water to cool down to prepare highly transparent polylactic acid blown film, keep high transparency, have high tensile strength simultaneously, and have easy tear property, the prepared film can be used for packaging materials such as packaging Flowers, vegetables, bread, fruit, candy, etc.; the lamination film is used for the lamination and molding of pulp tableware, portable paper bags, packaging folding boxes, and toilet paper; the film has complete biodegradability, expanding the application field of polylactic acid film, which has great potential Economic and Environmental Benefits

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