Preparation and properties of modified amine curing agent for epoxy paving materials

Based on the chemical modification of a bifunctional primary amine (BPA) curing agent with an unsaturated double-bond compound (UDC), this study investigated the effects of different UDC/BPA molar ratios on the molecular structures and curing reaction characteristics of the synthesized products, as well as the mechanical properties of the cured materials. Results indicated that UDC successfully grafted onto the primary amine sites of BPA via an addition reaction, forming less reactive secondary amine groups. This modification significantly reduced the reactivity of BPA, transforming the DSC curing exotherm from a single peak to a double-peak profile and increasing the apparent activation energy, thereby substantially prolonging the gel time and complete cure time of the system. As the UDC proportion increased, the tensile strength of the cured materials gradually decreased, while the elongation at break was significantly enhanced.