Synergistic effects of thermoplastic and nanoclay on the performance properties and morphology of epoxy resin

The present work investigates the properties and morphology of nanobent/poly(methyl methacrylate) (PMMA)/epoxy resin hybrid nanocomposites which were successfully prepared by solvent and ultrasonication methods. Nanobent ZS1 were added in amount of 1, 2, 3, and 4 wt% and 5, 10, and 15 wt% for PMMA. The fracture toughness (impact strength and critical stress intensity factor) and flexural properties were evaluated for epoxy composites. Obtained results showed improvement of the epoxy resin mechanical properties due to the addition of PMMA and nanobent. Composites containing 5 wt% of polymeric modifier or 1 wt% nanobent exhibited maximally improved properties. In the case of hybrid composites, synergistic effect was obtained with flexural strain at break and flexural energy to break of hybrid nanocomposite based on 1 wt% nanobent and 5 wt% PMMA. However, epoxy nanocomposites based on 2 wt% nanobent and 5 wt% PMMA showed synergism with IS and brittle fracture energy toward the composites with one modifier. Fourier transform infrared (FTIR) spectra analysis confirmed interactions between incorporated modifiers and reactive groups of the epoxy matrix. Moreover, scanning electron microscope (SEM) micrographs of hybrid epoxy nanocomposites exhibited a morphology with large plastic yielding associated with significant roughness of the fracture surface with embedment of nanobent in the polymer system. This study clearly demonstrates that the improvement of mechanical properties of the epoxy resin could be attributed to the synergistic toughening effect of PMMA and nanobent without deterioration of thermal stability. POLYM. COMPOS., 39:E2540-E2551, 2018. (c) 2018 Society of Plastics Engineers