Epoxy/polyurethane/clay ternary nanocomposites - effect of components mixing sequence on the composites properties

The present work investigates the mixing sequence of montmorillonite (MMT) and polyurethane (PUR) on epoxy resin (EP) properties. Mechanical properties were evaluated and structures analyzed by means of infrared spectroscopy (FTIR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The measured properties of all tested compositions were improved in comparison with unmodified epoxy resin. The best mechanical properties were exhibited by the compositions in which PUR was first mixed with EP before incorporation of MMT. The FTIR spectra indicated the formation of non-grafted interpenetrating polymer network structure. Moreover, XRD and TEM results confirmed the formation of intercalated structures and nanoclay exfoliation for obtained nanocomposites