A study on the peel strength of silane-treated silicas-filled epoxy adhesives

In this paper, the effect of silane-treated silicas and epoxidized soybean oil (ESBO) addition on adhesion properties of sili­cas-filled epoxy adhesives was examined. The silicas were treated by γ -methacryloxy propyltrimethoxy silane (MPS), γ -glycidoxy propyl trimethoxy silane (GPS), and γ -mercapto propyl trimethoxy silane (MCPS). Surface and structural properties of the adhesives were determined by using scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). The t-peel strength of the adhesives was estimated using the universal testing machine (UTM). And, the equilibrium spreading pressure, surface free energy, and specific surface area were investigated by BET methods with N₂/77 K adsorption. As a result, the peel strength of the adhesives was increased in the presence of silane-treated silicas in the adhesives compared to that of untreated silicas. This result indicated that the silane coupling agent played an important role in improving the dis­persion of silicas in epoxy adhesives. And, the adhesives treated by MCPS were superior to the others in adhesion.