s.m Mozaffari - PhD student, Department of Composites, Iran Polymer and Petrochemical Institute, Tehran, I.R. Iran
m.h Beheshty - Professor, Department of Composites, Iran Polymer and Petrochemical Institute, Tehran, I.R. Iran
s.m Mirabedini - Professor, Department of Color and Surface Coatings, Iran Polymer and Petrochemical Institute, Tehran, I.R. Iran

Among the methods of forming latent curing agent for epoxy resins, the encapsulation of the curing agent is a promising method. These systems have been used in one-part thermosetting adhesives or making prepregs which can be used in developing advanced composite materials. In this study, a new approach was proposed to reduce the disadvantage of thermoplastic polymer shell of microcapsules by using a thermosetting solid epoxy resin. The results of dynamic mechanical properties of these new microcapsule-cured epoxy resins showed that in the presence of microcapsules the cured epoxy resin systems became single-phase and its storage modulus did not reduced. Differential scanning calorimetry test also confirmed this one phase system. Scanning electron microscopic investigation of fractured surface of microcapsules-cured epoxy resin showed a relatively uniform morphology. Results also show that the height of tan δ peak of the cured epoxy resin by capsulated 1-methylimidazole curing agent is increased

Epoxy resin, Curing agent, Dynamic mechanical thermal analysis, Microencapsulation, Solid epoxy