Influence of 3-Glycidoxypropyltriethoxysilane on the Structural Organization of Epoxy-Silica Nanocomposites

Abstract

The structural properties of epoxy-silica nanocomposites of anhydride curing synthesized by the sol-gel method were studied using small-angle X-ray scattering and electron microscopy. It was shown that the aggregation processes change significantly during the formation of sols of silica nanoparticles (SP) by using 3-glycidoxypropyltriethoxysilane (GPTES) in the presence and absence of an epoxy oligomer in the system. The fractal aggregate types of each structural level are identified and their sizes are determined by the fractal analysis. It was found that there is a two-level and three-level fractal organization for GPTES-based sols, formed in the presence of an epoxy oligomer, depending on the content of SP. At the same time, aggregates with an average size of 10-11 nm are formed at the first structural level; SP form aggregates with an average size of 65-70 nm at the second level, while the size of the third-level aggregates is more than 250 nm.