Preparation and curing behaviour of microencapsulated curing agents for cold-mixed epoxy asphalt

Abstract

This study aimed to improve control over the curing behaviour of cold-mixed epoxy asphalt by using a microencapsulated curing agent (2-PZ@PC). Prepared through solvent evaporation, the 2-PZ@PC microcapsules had 2-phenylimidazole as the core material and polycarbonate as the shell material. The research examined the impact of core–shell mass ratio on microcapsule morphology and composition. Various equations, including the kinetics equation, Kissinger equation, Flynn–Wall–Ozawa, and Crane equations, were employed to assess the sustained release effect of 2-PZ@PC microcapsules on epoxy resin curing behaviour. Fluorescence microscopy and viscosity experiments were used to observe the release state of microcapsules and confirm the retardation phenomenon during construction. Optimal 2-PZ@PC microcapsules displayed a smooth spherical morphology and a maximum encapsulation rate of 32 wt% at a 1:1 core–shell ratio. The microencapsulated curing agent effectively regulated cold-mixed epoxy asphalt’s curing behaviour, enhancing retention time control and application reliability.

Keywords:

• Microcapsules
• curing behaviour
• kinetics
• cold-mixed epoxy asphalt
• curing agent

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by the Scientific and Technological Achievements Transfer and Transformation Project of the Chinese Academy of Sciences in Henan Province, China [No. 2021102], the National Natural Science Foundation of China [Youth Science Foundation Program No. 21908206], the Grant YLU-DNL Fund of China [No. 2021015], and the Key Science and Technology Project of Henan Province, China [No. 202102210213].