4. Conclusion

This article presents the latest work on bioadhesives based on citric acid alone and in combination with mono- and disaccharides (glucose and sucrose). Other carbohydrates, such as starch and hemicellulose fractions, can be considered as partners in citric acid bonding, as clearly demonstrated by the use of citric acid alone to bond wood, by reaction with wood constituents. It should be pointed out that there are several other types of wood adhesive that use citric acid: for example, the reaction mechanism of hexanediamine with citric acid enriched or not by the addition of glucose is known.