Development of Green Adhesives for Fibreboard Manufacturing, Using Tannins and Lignin from Pulp Mill Residues (original) (raw)

In order to reduce formaldehyde emissions from wood panels and to develop green adhesives, natural phenolic polymers of tannins and lignin have been investigated as substitutes of petrol-based chemicals used in wood panels. The potential of several wood barks, obtained from pulp mills as industrial wastes, has been evaluated for tannin extraction and further for their adhesive properties. Aqueous extractions were carried on wood barks of five different tree species on a laboratory scale – Aleppo pine barks led to the highest yield (15%) compared to spruce, Douglas fir, maritime pine and eucalyptus. Urea and sulfite used as water-additives favoured the extraction of condensed tannins, especially for spruce and Douglas fir barks. Eucalyptus barks presented the lowest tannins contents. Pyr-GC/MS of the bark extracts showed that Douglas fir and Aleppo pine tannins were mainly constituted of phenol and catechol tannins. The adhesive potential of these tannins was also established. Cookin...