Formaldehyde-free protein adhesive and preparation method thereof

Abstract

The invention discloses a formaldehyde-free protein adhesive and a preparation method thereof. The formaldehyde-free protein adhesive is composed of the following raw materials: degreased soybean mealprotein powder, trypsase, ficus proteinase, a dispersion medium water, sodium periodate, triethylenetetramine and ethylene glycol diglycidyl ether. A protein molecule is firstly degraded and then ismodified and recombined to obtain a pre-polymer, protein is sufficiently extended and a molecular active group is remarkably improved; the reaction activity is improved, the pre-polymer easily reactswith a crosslinking agent and the solubility and the water-retaining property are improved, so that the adhesive prepared by the preparation method provided by the invention has the advantages that the waterproof glue joint performance is high and the stability is high; and the waterproof requirements on an artificial board adhesive can be met and the dosage of a crosslinking agent is reduced, sothat the cost of the adhesive is reduced and the practical performance of the protein adhesive is ensured.

Description

technical field [0001] The invention relates to the technical field of wood-based panel adhesives, in particular to a formaldehyde-free protein 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 total output o...

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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.

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 the formation of a large number of weak interfaces. Layer, although the average strength meets the requirements, but the quality of the bonding in different areas of the wood-based panels varies greatly, the bonding strength is unstable, and the production efficiency is low.

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