Browsing by Author "Nuhiji, B"
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- ItemThe effect of a rapid heating rate, mechanical vibration and surfactant chemistry on the structure–property relationships of epoxy/clay nanocomposites(Multidisciplinary Digital Publishing Institute (MDPI), 2013-08-20) Nuhiji, B; Attard, DJ; Thorogood, GJ; Hanley, TL; Magniez, K; Bungur, J; Fox, BThe role of processing conditions and intercalant chemistry in montmorillonite clays on the dispersion, morphology and mechanical properties of two epoxy/clay nanocomposite systems was investigated in this paper. This work highlights the importance of employing complementary techniques (X-ray diffraction, small angle X-ray scattering, optical microscopy and transmission electron microscopy) to correlate nanomorphology to macroscale properties. Materials were prepared using an out of autoclave manufacturing process equipped to generate rapid heating rates and mechanical vibration. The results suggested that the quaternary ammonium surfactant on C30B clay reacted with the epoxy during cure, while the primary ammonium surfactant (I.30E) catalysed the polymerisation reaction. These effects led to important differences in nanocomposite clay morphologies. The use of mechanical vibration at 4 Hz prior to matrix gelation was found to facilitate clay dispersion and to reduce the area fraction of I.30E clay agglomerates in addition to increasing flexural strength by over 40%. © 2013 by the Authors. This is an open access article distributed under the Creative Commons Attribution License.
- ItemThe effect of alternate heating rates during cure on the structure-property relationships of epoxy/MMT clay nanocomposites(Elsevier, 2011-10-24) Nuhiji, B; Attard, DJ; Thorogood, GJ; Hanley, TL; Magniez, K; Fox, BThis paper investigates the effect of both the mixing technique and heating rate during cure on the dispersion of montmorillonite (MMT) clay in an epoxy resin. The combination of sonication and using a 10 degrees C/min heating rate during cure was found to facilitate the dispersion of nanoclay in epoxy resin. These processing conditions provided a synergistic effect, making it possible for polymer chains to penetrate in-between clay galleries and detach platelets from their agglomerates. As the degree of dispersion was enhanced, the flexural modulus and strength properties were found to decrease by 15% and 40%, respectively. This is thought to be due to individual platelets fracturing in the nanocomposite. Complementary techniques including X-ray diffraction (XRD), small angle X-ray scattering (SAXS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX). transmission electron microscopy (TEM) and optical microscopy were essential to fully characterise localised and spatial regions of the clay morphologies. (C) 2011 Elsevier Ltd.