EFFECT OF SILICA FILLER ON ALUMINUM ALUMINUM BONDING BY A SELF-VULCANIZABLE BLEND BASED ON CHLOROBUTYL RUBBER AND CARBOXYLATED NITRILE RUBBER

Silica filler improves the aluminum-aluminum bonding by a self-vulcanizable rubber blend based on chlorobutyl rubber and carboxylated nitrile rubber. The joint peel strength depends on the filler loading, the state of cure, the molding temperature, and the adhesive film thickness. The higher peel strength in the filled adhesive system is due to filler reinforcement resulting in tear path deviation and the formation of Si-O-Al linkage at the aluminum-adhesive interface. Maximum peel strength was obtained at 10 phr filler loading, when the molding temperature was 180-degrees-C and the molding pressure was 0.35 MPa.