Bioadhesive and method for its production

Abstract

According to the present invention, a method for producing an adhesive is provided, the method comprising the following steps: a) obtaining lignin-rich carbohydrate complexes (LCCs) by hot water extraction from softwood biomass, preferably spruce or Scots pine biomass, or hardwood biomass, preferably birch or beech biomass, obtaining lignin-rich carbohydrate complexes from bark (BLCCs) by hot water extraction from softwood bark, preferably spruce or Scots pine bark, or obtaining liquefied biomass by acid-catalyzed liquefaction of biomass, including wood sawdust powder, agricultural residues, plant stems, recycled cardboard, recycled paper, recycled wood, wood panels and wood bark sidestreams, into polyhydric alcohols and phenols;b) reacting the lignin-carbohydrate complexes, the lignin-rich carbohydrate complexes from bark, or the liquefied biomass obtained in step a) with a crosslinking or catalytic agent selected from the group consisting of: carboxylic agents, including citric acid, dicarboxylic acids, including adipic acid, organic acid anhydrides, tannins, tannic acid, and fatty acids of vegetable origin, including suberin and hexamethylenediamine, to produce said adhesive. Furthermore, the invention is directed to an adhesive produced by the method of the invention and its use as an adhesion agent in wood products, or as a coating agent in wood or mineral wool products.