Title: Nanomechanical behaviour and thermal degradation of nanoclays and supernanoclays enhanced marine gelcoat system

Authors: Seng Chai See, Zhong Yi Zhang, Hom Nath Dhakal, M.O.W. Richardson

Addresses: Advanced Polymer and Composites Research Group, Department of Mechanical and Design Engineering, University of Portsmouth, Portsmouth, Hampshire, PO1 3DJ, UK. ' Advanced Polymer and Composites Research Group, Department of Mechanical and Design Engineering, University of Portsmouth, Portsmouth, Hampshire, PO1 3DJ, UK. ' Advanced Polymer and Composites Research Group, Department of Mechanical and Design Engineering, University of Portsmouth, Portsmouth, Hampshire, PO1 3DJ, UK. ' Advanced Polymer and Composites Research Group, Department of Mechanical and Design Engineering, University of Portsmouth, Portsmouth, Hampshire, PO1 3DJ, UK

Abstract: Novel nanoclay reinforced unsaturated polyester gelcoats for marine vessels are evaluated in terms of their thermal and mechanical performance. In this study, mechanical and thermal tests have been employed to characterise different gelcoat systems with various loading levels of nanoclays with and without X-treatment. Differences in mechanical properties were determined by using nano-indentation testing which shown an increase in hardness compared to the control system. Thermal degradation characteristics were determined using a thermogravimetric analyser (TGA). An increase in thermal stability was observed for all nanocomposites compared to the control system. Additionally, differential scanning calorimetry (DSC) showed that the effect of inclusion of nanoclays is to hinder the structure of unsaturated polyester gelcoats and hence increase glass transition temperatures. Furthermore, X-treated supernanoclay is shown to be significantly more effective than untreated nanoclay. Enhancement of mechanical property and thermal degradation could be attributed to the grafting of hydroxyl groups (–OH) in the nanoclays with polymer chains.

Keywords: nanoindentation; thermogravimetric analysis; TGA; differential scanning calorimetry; DSC; X-ray diffraction; nanoclays; nanocomposites; nanomaterials; nanotechnology; unsaturated polyester gelcoats; marine vessels; thermal degradation; glass transition temperatures; hydroxyl groups; polymer chains.

DOI: 10.1504/IJMATEI.2009.024025

International Journal of Materials Engineering Innovation, 2009 Vol.1 No.1, pp.21 - 39

Published online: 24 Mar 2009 *

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