Project: From native wheat starch towards innovative adhesives for wood panels
The project aims at exploring fundamentals related to the modification of wheat starch from Lantmännen operations, and hence addressing the relevant questions needed to transform it to a bio-based adhesive system for the wood panel industry.
This project was concluded in December 2019.
Project manager Stergios Adamopoulos Other project members Reza Hosseinpourpia, Linnaeus University Arantxa Eceiza, University of the Basque Country, Spain Participating organizations Linnaeus University; University of the Basque Country, Spain Financier The Lantmännen Research Foundation Timetable 1 Jan 2018-31 Dec 2019 Subject Forestry and Wood Technology (Department of Forestry and Wood Technology, Faculty of Technology)
More about the project
The wood panel industry uses almost exclusively synthetic, petroleum-derived thermosetting adhesives, which are based on the reaction of formaldehyde with urea, melamine, phenol, or co-condensates. Stricter legislation on the carcinogenic formaldehyde as well as the consumer interest in healthy and sustainable products have forced the wood industry to find alternatives to amino-based adhesives. Developing good properties for bio-based adhesives is challenging and a cross-linker is required to increase both the adhesion and water resistance. For economic reasons, as for now, it is not viable to develop bio-based crosslinkers and among the potential synthetic ones, isocyanates seem to be the most popular for bio-based applications close to commercialization.
Among the different renewable materials, starch-based adhesives provide many advantages for solid wood and plywood industries, as they are easy to handle, are low cost and have low formaldehyde emissions. However, for panel applications they present several limitations such as lack of reactivity, bonding strength, storage stability and water tolerance. An extrusion, thermoplastic type of starch adhesive is now entering the market but shows several shortcomings associated mainly with the complexity of its production and also with the need of synthetic crosslinker (PMDI) at large quantities to reach the performance requirements at the same costs.
This project proposes a cost-effective chemical modification of wheat starch to improve its polymeric structure and adhesion properties, thus eliminating or minimising the need of a synthetic crosslinker.