A kind of formaldehyde-free soybean protein-based adhesive and preparation method thereof

Abstract

The invention discloses a formaldehyde-free soybean protein-based adhesive and a preparation method thereof, wherein the adhesive includes soybean meal powder, bromelain, soybean shell polysaccharide enzyme, dispersion medium water, sodium periodate, diethylenetriamine, ammonium Dialdehyde diglycidyl ether and curing agent. By adopting the preparation method of the present invention, the obtained formaldehyde-free soybean protein-based adhesive, the soybean meal molecules are firstly degraded and then modified and recombined to form a prepolymer, so that the protein is fully stretched, the molecular active groups are significantly increased, the reactivity is improved, and the solubility and Water retention is improved and toughness is increased. After adding an elastomer-based curing agent, the adhesive prepared has high toughness, high water-resistant bonding performance, and high stability; it can meet the water-resistant requirements of wood-based panel adhesives and reduce the amount of cross-linking agent. The cost of the adhesive ensures the practical performance of the protein adhesive.

Description

technical field [0001] The invention relates to the technical field of wood-based panel adhesives, in particular to a formaldehyde-free soybean protein-based adhesive and a preparation method thereof. Background technique [0002] my country is short of precious wood resources, but there are abundant plantation forest resources. The wood-based panels prepared by using plantation fast-growing wood and agricultural and forestry processing residues through adhesives are the main raw materials for furniture floors and interior decoration in the living environment. In 2016, The total output of wood-based panels in my country is 320 million cubic meters, accounting for about 50% of the world's total output. Based on the average production of 9 cubic meters of wood-based panels per ton of adhesive, the consumption of wood adhesives in my country in 2015 was about 40 million tons (solid content 50%), of which urea-formaldehyde resin and its modified products accounted for 20% of the ...

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Problems solved by technology

However, urea-formaldehyde resin also has obvious disadvantages, such as poor aging resistance, poor water resistance, and cannot be used to prepare wood-based panels for outdoor use.

[0003] The use of vegetable protein adhesives to prepare wood-based panels can solve the problem of free formaldehyde release from wood-based panels, but there are problems such as poor water resistance and bonding performance, and unstable production. This is because the raw materials used to prepare protein adhesives such as soybean meal and cotton meal 1. Due to poor protein solubility, large particles, and large molecular weight of peanut meal, the modification method of adding an external cross-linking agent cannot modify the matrix, resulting in uneven distribution of the cross-linked structure of the protein adhesive and poor toughness. A large number of weak interface layers and poor water retention capacity. Although the average strength meets the requirements, the bonding quality of different areas of wood-based panels varies greatly, the bonding strength is unstable, and the production efficiency is low.

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