Kinetic modeling of the crosslinking reaction of cycloaliphatic epoxides with carboxyl functionalized acrylic resins: Hammett treatment of cycloaliphatic epoxides

Cyclohexene oxide and benzoic/substituted benzoic acids were used as model compounds to study the reactivity of cycloaliphatic diepoxides with carboxyl functionalized polymers. A σ-ρ Hammett treatment of cycloaliphatic epoxides with substituted benzoic acids was used to investigate the reaction mechanism(s) of ester formation. The catalytic dependence on the acid strength was obtained via a H₀ Hammett-Deyrup acidity function. The σ-ρ Hammett treatment resulted in a positive ρ indicating that the transition state or the activated complex has a developing negative charge. This suggests that only the dissociated benzoic acid (or substituted benozic acids) is the attacking nucleophile.