In this paper, we report on the effect of curing agents on the miscibility, morphology, thermomechanical properties, and surface hydrophobicity of diglycidyl ether of bisphenol A (DGEBA)/poly­(ε-caprolactone) (PCL) blends. Two curing agents, 4,4′-diamino diphenylsulfone (DDS) and 4,4′-diamino diphenylmethane (DDM), were used. Studies revealed that the epoxy/PCL/DDM system was completely miscible due to the intermolecular hydrogen bonding interactions between carbonyl groups of PCL and hydroxyl groups of epoxy resin. On the other hand, the epoxy/PCL/DDS system exhibited phase separated matrix/droplet type morphology, primarily due to the intramolecular hydrogen bonding interactions within the epoxy phase between sulfonyl groups of DDS and hydroxyl groups generated during epoxy–DDS reaction. The storage modulus of the epoxy/PCL/DDM system was greater than that of the epoxy/PCL/DDS system, and the dependence of modulus on PCL content was more pronounced in the former. Moreover, the epoxy/PCL/DDM system exhibited better tensile properties and thermal stability.

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