Assessment of mechanical and healing behaviors of glass fibers-epoxy composite containing the microcapsules with the nanocomposite shell

In the current study, the effect of adding the encapsulated healing agent with neat polymeric and nanocomposite shells on the mechanical-healing features of glass fibers/epoxy composite under various loads was investigated. Therefore, the microcapsules with urea-formaldehyde (UF) nanocomposite shell containing the various weight fraction of silica nanoparticles (0, 1, 2, 3) were synthesized. After that, the flexural, tensile, and interlaminar shear strength (ILSS) samples were destructed by using the quasi-static penetration method with the damaging force of 500, 1050, and 2900 N, respectively. The maximum healing efficiency in the flexural loads belonged to the composite with the 3 wt% nanosilica on the surface of microcapsules, which was 83.9%. Also, it was found the increment in the weight fraction of silica nanoparticles had a negligible effect on the healing ability of composite under tensile loading. Achieving 135.8% healing efficiency in the composite with the 2 wt% nanosilica under the shear loads can be one of the most important findings in this work.     

Synthesis of Clay/Poly (styrene/2-ethylhexyl acrylate) Nanocomposite Latexes via Emulsion Polymerization

Silicon - In this research, nanocomposite latex based on polystyrene-co-2-ethylhexyl acrylate with layered silicate was synthesized by emulsion polymerization procedure. For increasing...     

Microcapsulated epoxy resin with nanosilica-urea formaldehyde composite shell

In this study, the epoxy microcapsules with the nanosilica (0, 1, 2, and 3 wt %)—urea formaldehyde composite shell were synthesized and then characterized by optical microscope (OM), field emission scanning electron microscope (FESEM), Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric analysis. According to the OM analysis, the without nanosilica microcapsules had the semitransparent structures and equal size distributions. Also, the formation of the microcapsule clusters and rupturing microcapsules in the sample containing 3 wt % nanosilica were observed by OM method. The FESEM analysis showed that without nanosilica, microcapsules had a smooth surface, whereas by increasing the percentage of nanosilica up to 2 wt %, the surface roughness was enhanced. It was also observed that on the surface of the microcapsules without nanosilica, two size ranges of the submicrocapsules with the average diameters of 1.12 μm and 208 nm were formed. By adding 1 wt % nanosilica, three size ranges of submicrocapsules were formed, with the average size of 2.63 μm, 824 and 179 nm. The interesting phenomena in the microcapsules containing 2 and 3 wt % nanosilica were the packing submicrocapsules with the polymeric shell and the formation of the microcapsule clusters, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48580.     

Improving the Flexural Properties of E-Glass Fibers/Epoxy Isogrid Stiffened Composites through Addition of 3-Glycidoxypropyltrimethoxysilane Functionalized Nanoclay

Silicon - This research work investigates the effect of silane functionalized nanoclay on the flexural response of E-glass/epoxy isogrid stiffened composite (IGSC). To do so, the sodium...