Synthesis of Cyanate Ester Microcapsules via Solvent Evaporation Technique and Its Application in Epoxy Resins as a Healing Agent

Bisphenol A cyanate ester/polyglycidyl methyacrylate (BADCy/PGMA) microcapsules were successfully fabricated via a solvent evaporation technique; herein, BADCy is the core material and synthesized PGMA is the shell material. Optimal BADCy/PGMA microcapsules with dense core–shell structures were implanted in the bisphenol A epoxy resin (E-51) matrix to fabricate the corresponding (BADCy/PGMA)/E-51 self-healing composites. Results revealed that the optimal BADCy/PGMA microcapsules presented a spherical shape and rough surface, with mean diameter of 31.5 μm and wall thickness of 2.2 μm. The core material of BADCy maintained its reactivity after being encapsulated by the shell of PGMA. The BADCy/PGMA microcapsules also presented relatively good thermal stability and proper mechanical stability. Moreover, the fabricated (BADCy/PGMA)/E-51 composite with 8 wt % BADCy/PGMA microcapsules possessed relatively good self-healing performance.