Chemically induced phase separated morphologies in epoxy resin-hyperbranched polymer blends

The morphology build-up in toughened epoxy blends using reactive hyperbranc hed dendritic polymers (HBP) and amine-cured epoxy resins has been investig ated in the present work. By changing the processing conditions or the surf ace chemistry of the modifier, very different morphologies can be obtained, ranging from homogeneous blends to coarse two-phase systems. The morpholog y characterised by electron and optical microscopy has been interpreted com bining constitutive equations for phase separation and thermodynamic modell ing of phase interactions. The latter model, based on the Flory-Huggins lat tice theory, was modified in order to take into account the addition reacti vity of the HBP modifiers. This approach proved successful and can be used as a tool for final morphology prediction in any reactive blend formulation .