Experimental investigation on the self-healing properties of ester-exchanged vitrimeric CFRP laminate with microchannels

Epoxy vitrimer theoretically achieves an unlimited healing cycle drawing support from dynamic molecular chains. The healing conditions required for microvascular systems are variable and flexible. Current research has often focused on a single healing system, further exploration is needed for a dual healing system that combines the advantages of both. In this study, the effects of curing agent and catalyst content on the performances of vitrimer, as well as the healing parameters on the healing efficiency were studied. And then the vitrimeric CFRP (vCFRP) laminates with microchannels were prepared, and the three-point bending tests were implemented to characterize the healing efficiency of CFRP with a single and dual healing system. The results indicated that the cured vitrimer exhibited the best comprehensive performance when the molar ratio of reactants was 1:1:0.07. The healing temperature had the greatest impact on the healing efficiency of vitrimer, followed by the catalyst content and the healing pressure. The two healing systems could improve the mechanical properties of laminates, especially the healing efficiency of CFRP with dual healing system reached 134.5 %. The healing agent in the microchannels could heal micro-damage, and the healability of the vitrimer could still be utilized after the healing agent was exhausted.