WHAT IS THE CHALLENGE?Wood adhesives are used in large volumes worldwide in a large number of indoor and outdoor applications such as furnitures, construction of houses, etc. The most commonly used adhesives are petroleum-based phenol- and urea-formaldehyde resins. The problem is that emission of formaldehyde during production and use of such adhesives pollutes the working as well as living environments. There is also evidence that formaldehyde is a human carcinogen. Development of formaldehyde-free adhesives from natural resources but having a similar gluing efficiency as the synthetic adhesives is thus necessary.HOW CAN THE PROJECT CONTRIBUTE TO A SOLUTION
The project draws on the knowledge about strong, water-resistant adhesives produced in nature by living organisms. One of them is lignin - among the most abundant natural polymer on earth and acts as the natural glue in woody plants. It is hence obvious to consider the use of lignin even for application as commercial adhesive. The monomeric components of lignin are indeed similar in structure to phenol, however lignin is less reactive. The project aims to look at the possibility to modify the lignin to make it more reactive for cross-linking with other molecules and to evaluate the modified structures for gluing properties. The modification can be performed using enzymes that are commonly produced by fungi. Cross-linking of the modified lignin with other molecules will be based on the knowledge on the structure of proteinaceous “super-glues” produced by marine organisms such as mussels and barnacles to anchor themselves to rocks. Development of strong and environmentally benign wood adhesives from lignin would thus potentially result in a reduction in the use of formaldehyde based adhesives.
WHO WILL BENEFIT FROM THE RESULTS?
The results would be of potential interest and use to the manufacturers and users of adhesives and wood composites, the forest industry, chemicals and biotechnology industry, chemicals inspectorate, and also to the scientific community in general.
