Preparation of soy-based adhesive
Soy-based adhesive was prepared according to a method already reported [17]. A three-neck round-bottom flask equipped with a mechanical stirrer, a thermometer and a condenser was charged with water (187 g), sodium dodecyl benzene sulfonate (0.8 g), CaO( 1.9 g) and NaOH (3.7 g) to 701C. Soy flour (80 g) was then charged to the rapidly stirring solution. The mixture was heated to 901C over 15 min, with rapid agitation, and held between 881C and 921C for 3 h. The mixture was cooled to 351C in an ice bath. The solid content of the resulting soy-based adhesive was 3071%