Effect of the dispersion of self-healing microcapsules on tensile properties of microcapsules filled composites

In order to improve the dispersion of ethylidene-2-norbornene (ENB) based self–healing microcapsules in the epoxy, KH560 coupling agent was chosen to modify the surface of ENB microcapsules. The dispersion of KH560-ENB microcapsules and their influence on tensile property of KH560-ENB/Epoxy composites were studied. The results show that, the tensile fracture strength, tensile modulus and elongation at break of ENB/Epoxy composites, decrease when the mass ratio of ENB microcapsules to epoxy increases to no more than 5%. The falling slopes of those three tensile properties vary with pre-curing temperature for ENB/Epoxy composites. The linear coefficient of cumulative distribution of KH560-ENB microcapsule in epoxy is 0.9945, nearly to 1, showing better dispersion. Furthermore, tensile fracture strength and tensile modulus of KH560-ENB/Epoxy composites increase by 19.1% and 6.6%, respectively. According to SEM observations of KH560-ENB/Epoxy cross section, the interface between KH560-ENB microcapsules and epoxy is well bonded.