Abstract
The aim of this study is to design dismantlable structural epoxy adhesives with heat-resistant adhesive properties. Epoxy resin formulations using glycidyl phthalimide (GPI) with high polarity of imide structure as a mono-functional epoxy possessed relatively high Tg and reduced rubbery modulus of the resin at temperature over Tg, compared to the case using other mono-functionalepoxies. Curing agents also had an important role on the heat softening behavior. The combination of dicyandiamide/dichlorophenyldimethylurea as the curing agents showed good balance on high Tg and softening over Tg. These findings led to the cured resin composition including 25% of GPI, which possessed Tg over 80℃, modulus over 3GPa at glass state, and rubbery modulus lower than 2MPa. Consequently, the combination of the resin formulation with GPI and 10% of expandable graphite enabled both good dismantlability over 200℃ by thermal expansion of the graphite and high shear adhesive strength of over 20MPa at 80℃.
