Modified starch adhesive and method for preparing same

Abstract

The invention discloses a modified starch adhesive and a method for preparing the same. The modified starch adhesive comprises the following components by weight: 30-50 parts of corn starch, 80-120 parts of deionized water, 25-40 parts of sodium hypochlorite solution, 0.5-2 parts of epichlorohydrin, 30-70 parts of polyvinyl acetate emulsion, 10-30 parts of epoxy resin, 2-7 parts of tertiary amine catalyst, 5-15 parts of filler, 0.2-1 part of surfactant, and 0.2-0.6 part of preservative, wherein the sodium hypochlorite solution serves as the oxidant, the polyvinyl acetate emulsion serves as the high-cohesive-energy reinforcement component, and the epoxy resin servers as the water-tolerant modified component. The method for preparing the modified starch adhesive comprises the following steps: mixing the oxidized starch emulsion prepared in advance, the polyvinyl acetate emulsion and the epoxy resin according to proportion uniformly, adding the catalyst, the filler and the preservative, and stirring quickly and uniformly. The modified starch adhesive disclosed by the invention has the advantages of high shear strength, high water-tolerant shear strength, moderate viscosity, good liquidity, moderate primary drying time, low cost and excellent integrated performance.

Description

technical field [0001] The invention relates to a modified starch adhesive and a preparation method thereof. It specifically relates to a new type of modified starch prepared by using oxidized starch emulsion as the main glue, polyvinyl acetate as the high cohesive energy reinforcing component, epoxy resin as the water resistance modifier, and adding stabilizers, fillers and preservatives. A starch adhesive belongs to the field of wood adhesive preparation. Background technique [0002] my country is a big grain country with abundant cornstarch resources and low prices. As a modified component of classic adhesives, starch has long been used; as an adhesive, modified starch has also been widely used in the production of corrugated boxes. Starch is a homopolymer formed by the dehydration condensation of D-glucose monomer with a molecular weight of 10 6 ~10 7 Magnitude. C per glucose unit 2 、C 3 and C 6 Each starch has a hydroxyl group, so each starch molecular chain co...

AI Technical Summary

Problems solved by technology

Generally, the grafted chains with high cohesive energy are mostly polar, and the water resistance is not good; while the grafted chains with good water resistance are generally non-polar, and the bond strength is not significantly improved.

Moreover, the grafting reaction generally requires a free radical initiator to be carried out under high temperature conditions. At this time, the starch gelatinizes at high temperature, the viscosity increases sharply, the fluidity of the system becomes poor, and the steric hindrance increases, making it difficult for the grafting reaction to proceed smoothly.

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