The development of natural adhesives derived from non-fossil resources is very important for the future, for a number of reasons: firstly, for ecological reasons; secondly, for human health reasons; and thirdly, to enable sustainable development, with renewable materials and therefore not petroleum derivatives. In addition, adhesives must bond flawlessly without using harmful chemicals. The literature presents an increasing number of formulations, tests and new types of wood adhesives based on renewable substances, such as tannins, lignin, proteins, starch, etc.
Citric acid has recently come under particular scrutiny for its use in bio-based wood glues, but also directly as a wood glue. Citric acid is a tricarboxylic acid.
The first to discover the use of citric acid in this context was Professor Umemura's research group in Japan in 2012.
. This group, along with other research groups in France, China
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