Self-Healing Imidazole-Cured Epoxy Using Microencapsulated Epoxy-Amine Chemistry

Area of Science:

• Materials Science
• Polymer Chemistry
• Mechanical Engineering

Background:

• Epoxy resins in reactors degrade due to mechanical stress, thermal variations, and UV exposure, leading to cracking and failure.
• Extending the service life of reactors necessitates enhancing the damage resistance of epoxy resin components.

Purpose of the Study:

• To develop a novel self-healing imidazole-cured epoxy resin for reactor applications.
• To investigate the efficacy of electrospraying-interfacial polymerization (ES-IP) for microencapsulating epoxy and amine healing agents.
• To optimize microcapsule parameters (size, ratio, concentration) for maximum healing efficiency and thermal stability.

Main Methods:

• Utilized a double-nozzle electrospraying technique for simultaneous microcapsule preparation.
• Synthesized epoxy and amine microcapsules via ES-IP.
• Evaluated self-healing performance by varying microcapsule characteristics and assessing healing efficiency.
• Investigated the impact of microcapsule addition on thermal stability and mechanical properties (tensile strength).

Main Results:

• The double-nozzle method successfully produced microcapsules with controllable sizes ranging from 20 to 200 μm.
• Optimal conditions (10.0 wt% of 50–100 μm microcapsules) yielded 100% self-healing efficiency in the imidazole-cured epoxy.
• While tensile strength decreased slightly, the addition of microcapsules significantly enhanced high-temperature aging resistance.

Conclusions:

• Developed a highly effective self-healing epoxy resin for reactors using microencapsulated healing agents.
• The ES-IP technique and double-nozzle system are viable for producing tailored microcapsules for self-healing materials.
• The self-healing epoxy demonstrates potential for improving the durability and longevity of reactor components, particularly under thermal stress.