23c Influence of Interfacial Reactivity and Viscoelastic Response on Adhesion

E. Jason Robinette, Andres Bujanda, Robert Jensen, and Steven McKnight. Materials Division, Army Research Laboratory, Attn: AMSRD-ARL--WM-MA, Building 4600, Aberdeen Proving Ground, MD 21005

The strength of an adhesive bond strongly depends on the viscoelastic properties of the adhesive and its chemical interaction with the substrate. In this work, we present initial attempts to correlate interfacial bonding and adhesive viscoelastic parameters on the adhesion of urethane-acrylate adhesives to glass substrates. Interfacial bonding was controlled through silane chemistry by treating substrates with various ratios of reactive and non-reactive silanes. Dynamic mechanical analysis (DMA) was utilized to obtain WLF viscoelastic constants for the adhesive. A 90° peel test correlated peel strength and surface reactivity for various strain rates under ambient conditions. It was found that strain rate influenced the effect of surface reactivity on peel strength and the mode of failure (adhesive vs. cohesive). Future work will investigate several peel temperatures and use the viscoelastic constants to generate master curves isolating the effects of strain-temperature and interfacial bonding of the adhesive with the surface.