Recyclable, high adhesive strength small molecule rosin-based epoxy resin with AIE properties

The utilize of epoxy resins always necessitates the aid of petroleum-based curing agents to facilitate cross-linking and engender an irreversible tridimensional network structure. However, this characteristic, in turn, imposes the constraint of recyclability in their applications and hinders sustainable development. Creating a durable and repeatedly useable epoxy resin adhesive that can withstand mild bonding conditions lingers a significant challenge. In this work, a novel rosin-based epoxy resin (HAR-EP x ) was successfully prepared from hydrogenated acrylic rosin (HAR) and epoxy resin (EP x ) based on the structure of the hydrogenated phenanthrene ring with large steric hindrance and low cross-linking density. The HAR-EP x prepared in this study exhibits several remarkable properties, such as outstanding heat resistance (T d  = 354 °C), exceptional UV–visible light transmittance. HAR-EP x can be applied to adhesives without curing agents, and was characterized by mild bonding conditions (85 °C, 1.5 min), high mechanical properties (adhesion strength up to 4.306 MPa), and excellent reusability that retains over 80 % bonding strength even after undergoing 6 cycles. Moreover, it exhibits an intriguing characteristic, that is, it emits intrinsic cyan-green fluorescence when subjected to UV excitation, attributed to aggregation-induced emission (AIE).