Epoxy reinforcement with silicate particles: Rheological and adhesive properties – Part I: Characterization of composites with natural and organically modified montmorillonites

Rheological and adhesive properties of epoxy oligomer–montmorillonite (MMT) nanocomposites containing 2 and 5 wt% of natural and organomodified clay were studied. Ultrasound treatment of epoxy–clay systems was used for their homogenization. According to rheological data, ultrasound stirring allows the development of well-dispersed systems in the case of organomodified MMT. Sonication of composites with natural clay is inefficient and leads to a poorly dispersed structure. X-ray data demonstrate increases in the interlaminar spacing for organomodified MMT (up to 2 times), which is indicative of MMT intercalation. Clay addition leads to 40–65% increase in the shear adhesion strength of the cured epoxy resin. The sonication influence on the shear adhesion strength of the system with 2 wt% of any clay is very small. Ultrasound stirring of the systems with 5 wt% of clay results in higher values of adhesion for organomodified MMT.