Synthesis of IPDI@PU Microcapsule Curing Agent and Its Curing Behavior for Epoxy Resin

ABSTRACT The development of latent curing agents is essential for advancements in industrial applications. In this study, we synthesize the IPDI@PU microcapsule curing agent with a regular spherical morphology and a uniform size distribution through interfacial polymerization using a lignin‐stabilized O/W Pickering emulsion as a template. The encapsulation of IPDI within the PU shell effectively inhibits its curing activity. Furthermore, the presence of the PU shell does not change the rapid reaction kinetics of the curing system. Importantly, after a storage period of 30 days at 40°C, the curing degree of the IPDI@PU/EP system is measured at only 6.4%, indicating excellent storage stability and great potential for practical applications.