I.H. Hafez, H. Yang, W.T.Y. Tze
University of Minnesota, US
lignin, adhesives, green adhesives, polymers
When woody biomass is enzymatically treated to release from its polysaccharide components fermentable sugars for bio-alcohols and other chemicals production, it typically leaves behind in the waste stream solid residues that are rich in lignin. Lignin is a natural phenolic binder for cell walls in woody plants, and thus it is not surprising that utilization of lignin as adhesives has long been investigated. The research goal of this study was to examine technical feasibility of directly utilizing saccharification residues of woody biomass for adhesive applications. In this study, we attempted to 1) simplify the preparation process by directly utilizing lignin-rich residues of biomass for adhesives without having to pre-purify lignin, and 2) alleviate reactivity issues by pre-converting lignin-rich materials into nano-scale elements for increased surface areas. These two approaches constitute the new aspects of our research contributions. Findings from this study show that a fully biobased adhesive could be prepared from saccharification residues, providing a potential alternative to synthetic adhesives and increasing economic viability of the biochemical conversion of biomass.