A cyanate ester/microcapsule system with low cure temperature and self-healing capacity

Microcapsules filled with epoxy resin were blended into cyanate ester resin to produce systems with low cure temperature and self-healing capacity. A 4,4′-diaminodiphenylsulfone (DDS) curing agent was adopted for the systems. The mechanical properties, thermal stability and self-healing ability of the system cured at low temperature were investigated. Cyanate ester systems with 2.5 wt% and 5.0 wt% microcapsules (MCs) demonstrated an 11~43% increase in fracture toughness (KIC) relative to the neat resin cured at high temperature, and exhibited slightly lower thermal stability than the neat resin. The self-healing ability of cyanate ester with MCs was influenced by MC content and healing temperature, although for a formulation with 5.0 wt% MCs, recovery of 85% of the original fracture toughness was achieved by heat treatment of fractured samples for 1 h at 220 °C.