Preparation and curing behavior of latent 2‐PhIm‐PS microcapsule curing agent for epoxy resin.

A core–shell microcapsule latent epoxy curing agent (2‐PhIm‐PS) is obtained by solvent evaporation method with 2‐phenyl imidazole (2‐PhIm) as the core material and polystyrene (PS) as the wall material. The microcapsule parameters, morphology, structure, curing behavior, and the mechanic properties of cured epoxy resin with this microcapsule latent curing agent were characterized through comparing with 2‐PhIm. The particle size distribution of the microcapsule is narrow, the average particle size is about 10.56 μm, and the core material content is 23%. The prepared 2‐PhIm‐PS microcapsule curing agent has excellent latent curing properties. It can completely cure epoxy resin E‐51 within 10 min at 130°C, and its latent period can be more than 40 days at room temperature. In addition, the curing kinetics of one‐component epoxy resin curing system (E‐51/2‐PhIm‐PS) composed of 2‐PhIm‐PS microcapsules and epoxy resin E‐51 is also studied by using Kissinger equation, Flynn–Wall–Ozawa and Crane formula. The results provide an outline for the evaluation on the applicability of the microcapsule curing agent of 2‐PhIm‐PS for epoxy resin. [ABSTRACT FROM AUTHOR]