Development of self-healing epoxy composites via incorporation of microencapsulated epoxy and mercaptan in poly(methyl methacrylate) shell

• Published in: Polymer testing Vol. 73; pp. 395 - 403
• Main Authors: Ahangaran, Fatemeh, Hayaty, Mehran, Navarchian, Amir H., Pei, Yutao, Picchioni, Francesco
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2019
• Subjects: Epoxy composite; Healing agent; Mechanical properties; PMMA microcapsule; Self-healing behavior; Mechanical properties; Epoxy composite; Healing agent; Self-healing behavior; PMMA microcapsule
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2018.11.041

Self-healing composites based on epoxy resin containing poly(methyl methacrylate) (PMMA) microcapsules filled with healing agents were prepared. The effect of healing agents microcapsules on mechanical properties and self-healing behavior of epoxy composites were investigated in this work. Epoxy and mercaptan as curing agent were microencapsulated in PMMA shell as two-component healing agent through internal phase separation method, and then, epoxy composites containing 2.5, 5, 7.5 and 10 wt% of healing agent microcapsules were prepared. The fracture toughness and healing efficiency of these composites were measured using a tapered double cantilever beam (TDCB) specimen. The results indicated that about 80% healing efficiency was achieved with 10 wt% PMMA microcapsules at room temperature after 24 h. The tensile strength of the epoxy with 2.5 wt% PMMA microcapsules increased initially and then decreased gradually with increasing microcapsules content up to 10 wt% PMMA microcapsules. DSC results also indicated that this system has good potential for spontaneous self-healing performance at room temperature. •Low viscosity epoxy and mercaptan were encapsulated in PMMA shell, separately.•Fracture toughness of epoxy composites increased by the crack pinning mechanism around the broken PMMA microcapsules.•Healing efficiency of epoxy composites increased with increase in PMMA microcapsules concentration.