Synthesis of Reactive Modifiers and Their Effects on the Mechanical and Interfacial Bonding Properties of Epoxy Adhesives

Considering the workability, mechanical and bonding properties of epoxy adhesives, four prepolymers ( PPM) with low epoxy value and high hydroxyl content were prepared using trimethylolpropane triglycidyl ether (TMPGE) and 1, 4-butanediol ( BDO) by tuning the molar ratio and reaction time. The PPM was characterized by1 H-NMR, hydrochloric acid-acetone method, and gel permeation chromatography (GPC). The effect of PPM on the workability, mechanical, bonding properties and the surface properties of the modified epoxy adhesives was further investigated. The results showed that prolonging the reaction time and increasing the BDO amount resulted in larger molecular weight and lower epoxy value of the products. After PPM modification, the exothermic temperature of the adhesives was reduced, the operability time was increased, and the ductility of the cured epoxy was significantly increased. PPM modification also resulted in a lower contact angle and a higher polar component of the cured epoxy surface. XPS analysis showed that the PPM significantly increased the hydroxyl content of the cured epoxy. The bond strength of the adhesive to the wet mortar matrix increases more than double by PPM addition. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.