Improving Adhesion between Epoxy Adhesive Compositions and Aluminum Using Epoxy- and Amino-Alkoxysilane Promoters

Two ways of using 3-glycidoxy propyltrimethoxycilane and 3-aminopropyltriethoxysilane promoters for improving adhesion between epoxy adhesive compositions cured using anhydride and amine hardeners and D16AT aluminum alloy are considered. The work of adhesion and free surface energy of epoxy adhesive compositions with promoters are determined. The possible reactions of the promoters to the components of the adhesive compositions and a metal surface are studied. A probable mechanism of bonding epoxy adhesives and a substrate is proposed. It is shown that preliminary treatment of the aluminum alloy surface with an aqueous alcohol solution of a promoter is the most effective way to increase adhesive shear strength.