Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: May 13, 1998
Publication Date: N/A
Technical Abstract: Several studies on the use of soybean materials in plywood adhesives have been done in the last decade. However, no study has been done on soy-based adhesives that are applied by foam extrusion, a relatively new technique that appears to have several advantages over other popular modes of glue application. Foamed plywood glues currently use animal blood protein as their only extender. The object of this research was to determine if soy proteins could replace animal blood proteins in foamed glues. Our laboratory is presently evaluating soy protein products (flour, concentrates, isolates) as possible replacements. Foaming capacities and stabilities of 1% solutions of several soy protein sources and animal blood protein were tested at pH 7.0 (standard) and 10.0 (typical pH of plywood glues). Soy proteins generally produced more foam volume and foams with greater stability than animal blood protein at both pH levels. Molecular weights and amino acid compositions of the proteins were correlated to the foam test results, with mixed results in an attempt to determine structure/function relationships. Subsequently, the best foaming soy protein products were evaluated in plywood test panels manufactured at various glue spreads, assembly times and hot press times. It appears that the soy flour and concentrate are the most promising protein sources to replace animal blood in foamed plywood glues, in terms of foam properties and adhesive performance, with further studies ongoing.