Synergistic effect of the strength increasing of layer fiberglass model samples by reinforcing the epoxy binder and amine hardener with carbon nanotubes and their oxidized forms

The strength characteristics of model samples of fiberglass with epoxy binder RH 285 and hardener LH 286 reinforced carbon nanotubes (CNTs) anodically oxidized and the initial, respectively, were studied. CNTs are characterized by Raman and X-ray photoelectron spectroscopy. It is shown that the oxygen content and the specific surface area of CNTs change in the opposite to the amount of transmitted electricity in the range of 30–20 A h/kg. It was found that the synergistic effect of increasing the strength occurs when the initial CNTs are added into the amine hardener by ultrasonic treatment and anodically oxidized CNTs into epoxy resin (mixing on a three-roll mixer). This effect is because the amine hardener plays the role of surfactant in relation to CNTs, orienting the carbon part to CNTs, amine outward, i.e., preventing agglomeration of CNTs. The same effect is observed for oxidized CNTs in epoxy resin (charged CNTs are repelled), and oxygen-containing groups catalyze the polymerization of epoxy resin.