Protein Adhesives: Investigation of Factors Affecting Wet Strength of Alkaline Treated Proteins Crosslinked with Glyoxal

Abstract

Proteins obtained as side-products from starch production (potato and corn proteins) were investigated for wood adhesives application. To improve the wet strength of protein-based adhesives, glyoxal was added as a crosslinking agent. The effect of glyoxal on the wet strength of protein-based adhesives was investigated at different pH, protein: glyoxal ratios and solid content. The alkaline pretreatment of proteins was carried out by two different methods which reduced the molecular weight of proteins to different extents. The effect of molecular weight reduction on the wet strength of protein-glyoxal adhesives was also observed. It was found that pH level affects wet strength more significantly compared to solid content and protein-to-crosslinker ratio. Potato and corn proteins crosslinked with glyoxal showed maximal wet strength results in an acidic pH range

Effect of Mat Moisture Content, Adhesive Amount and Press Time on the Performance of Particleboards Bonded with Fructose-Based Adhesives

“…Research on renewable, bio-based adhesives is an extremely active field aiming to provide a solution from a bioeconomy perspective [ 16 , 17 ]. For example, numerous promising wood adhesives were recently reported based on natural biopolymers such as lignin [ 18 , 19 ], tannin [ 20 , 21 ], proteins [ 22 , 23 ], starch [ 24 , 25 ], cellulose derivatives [ 26 ] or other carbohydrates [ 27 ]. However, comparable to the success story of formaldehyde-based adhesives [ 28 ], the potential adoption of bio-based adhesives in the wood-based panel market will be driven by their functional performance and not merely by the green credentials of renewable adhesives [ 29 ].…”