Phenolic resin adhesive synthesized through in situ alkali lignin autocatalysis and preparation method of phenolic resin adhesive

Abstract

The invention discloses a phenolic resin adhesive synthesized through in situ alkali lignin autocatalysis. A preparation method of the phenolic resin adhesive comprises the following processes of (1) crushing a biomass material, pickling by using a sulfuric acid, filtering and drying to obtain a filter residue; (2) fully reacting an alkali liquor with the filter residue and then filtering to obtain an alkali lignin liquid; (3) directly adding phenol to the alkali lignin liquid, carrying out phenolic in situ modified reaction; (4) directly adding a formaldehyde solution to a phenolized lignin solution and carrying out molecular in situ polymerization; and (5) adding a little of formaldehyde capture agent urea, further reacting, dewatering and discharging to obtain the lignin-modified phenolic resin adhesive. The processes of alkali lignin molecular extraction and in situ modification and in situ synthesis of the phenolic resin adhesive are continuous and the efficiency is greatly improved. Meanwhile, a catalyst does not need to be added in the processes of in situ modification and synthesis of alkali lignin to form phenolic resin, so that autocatalytic reaction is achieved.

Description

technical field [0001] The invention relates to the fields of materials and chemical industry, in particular to a phenolic resin adhesive obtained by extraction of alkali lignin molecules, in-situ autocatalytic modification and autocatalytic synthesis and a preparation method thereof. Background technique [0002] In today's world, as a non-renewable resource, the price of petroleum continues to soar, which leads to higher and higher production costs of phenolic resin adhesives. As one of the important raw materials of phenolic resin adhesives, the price of phenol has remained high for a long time. In order to reduce the production cost of phenolic resin adhesives, finding other cheaper raw materials to replace phenol has become a very popular research topic at present. With the continuous development of society, green environmental protection is more required by all parties in the society. For this reason, it has become a trend to use more natural polymers instead of phenol...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the disadvantages of agglomeration and activity reduction caused by re-dissolving lignin solids after drying in the traditional method, and adopts the method of pretreatment to remove sugar substances and metal ions firstly, eliminating the need for acid-precipitated lignin And its re-drying process; overcome the complex process of adding catalysts in the traditional method of lignin molecular modification and polymerization with formaldehyde, and provide a kind of alkali lignin molecule in-situ modification and polymerization self-catalysis for efficient synthesis of phenolic resin adhesive The method does not require external catalysts; at the same time, a high proportion of lignin molecules replaces phenol molecules, realizing a low-cost and environmentally friendly synthesis process of phenolic resin adhesives

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