A kind of preparation method of polylactic acid base adhesive

Abstract

The invention belongs to the technical field of adhesive preparation, and discloses a preparation method of a polylactic acid-based adhesive. The method comprises the following steps: ultrasonically dispersing 300-400 parts by weight of graphene oxide coated cation starch in 15-25 parts by volume of trichloromethane under an ice water bath condition without stirring; adding 3000-4000 parts by weight of polylactic acid into 15-25 parts by volume of trichloromethane, and carrying out ultrasonic treatment while stirring until the polylactic acid is completely dissolved; adding citric acid into the above obtained polylactic acid solution, continuously stirring the citric acid and the polylactic acid solution for 3.5-4.5 h, adding the obtained uniformly-dispersed graphene oxide coated cation starch solution into the above obtained mixed solution, and carrying out closed stirring for 3.5-4.5 h; and pouring the finally obtained mixed solution into a vessel, and standing the vessel in a ventilating place to obtain a glue film sample which is the polylactic acid-based adhesive. The preparation method has the advantages of wide sources of raw materials, low influences on the environment, according with the green, nontoxic and environmentally-friendly development idea, increase of the mechanical strength of the adhesive, improvement of the crystallinity and the thermal stability of the polylactic acid, and great development values.

Description

technical field [0001] The invention belongs to the technical field of adhesive preparation, and in particular relates to a preparation method of a polylactic acid-based adhesive. Background technique [0002] Adhesives are a necessity in daily life. At present, most adhesives on the market contain free formaldehyde. The content of free formaldehyde is high, which brings great harm to the environment and human health, and it is difficult to meet the needs of environmental protection. Therefore, green and environmentally friendly adhesives are the future development direction. [0003] Polylactic acid is a completely biodegradable green material with good mechanical properties, biocompatibility, and light transmission. However, polylactic acid has poor crystallinity and is relatively brittle, so the bonding performance of pure polylactic acid adhesives is not ideal. [0004] As a renewable natural green material, starch has the advantages of wide sources, sufficient output,...

AI Technical Summary

Problems solved by technology

However, polylactic acid has poor crystallinity and is relatively brittle, so the bonding performance of pure polylactic acid adhesives is not ideal.

[0004] As a renewable natural green material, starch has the advantages of wide sources, sufficient output, low price, non-toxic and pollution-free, good adhesion and film-forming properties, low initial adhesion, slow drying rate, brittle and viscous film-forming substances. Weak bonding strength, low solid content, poor water resistance (a large number of hydrophilic hydroxyl groups contained in the main chain of starch molecules, it is easy to combine with water molecules, thereby significantly reducing the bonding strength), poor stability and fluidity (starch Adhesives will produce retrogradation after long-term storage, which is due to the formation of hydrogen bonds between starch molecules and the re-formation of microcrystalline bundles, so the viscosity of the system increases) and other shortcomings limit its application range

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