Table of Contents
Journal of Polymers
Volume 2013 (2013), Article ID 183463, 17 pages
http://dx.doi.org/10.1155/2013/183463
Research Article

Investigation of Cure Reaction, Rheology, Volume Shrinkage and Thermomechanical Properties of Nano-TiO2 Filled Epoxy/DDS Composites

1Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Cochin, Kerala 682022, India
2Leibniz-Institute for Polymer Research Dresden, Hohe Strare 6, 01069 Dresden, Germany
3School of Chemical Sciences, Mahatma Gandhi University, Priyadarshini Hills, Kottayam, Kerala 686560, India
4Centre for Nanoscience & Nanotechnology, Mahatma Gandhi University, Priyadarshini Hills, Kottayam, Kerala 686560, India

Received 26 March 2013; Accepted 2 July 2013

Academic Editor: Jae-Woon Nah

Copyright © 2013 Jyotishkumar Parameswaranpillai et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The cure reaction, rheology, volume shrinkage, and thermomechanical behavior of epoxy-TiO2 nanocomposites based on diglycidyl ether of bisphenol A cured with 4,4′-diaminodiphenylsulfone have been investigated. The FTIR results show that, at the initial curing stage, TiO2 acts as a catalyst and facilitates the curing. The catalytic effect of TiO2 was further confirmed by the decrease in maximum exothermal peak temperature (DSC results); however, it was also found that the addition of TiO2 decreases the overall degree of cure, as evidenced by lower total heat of reaction of the cured composites compared to neat epoxy. The importance of cure rheology in the microstructure formation during curing was explored by using rheometry. From the PVT studies, it was found that TiO2 decreases the volume shrinkage behavior of the epoxy matrix. The mechanical properties of the cured epoxy composites, such as tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, and fracture toughness of the polymer composites, were examined. The nanocomposites exhibited good improvement in dimensional, thermal, and mechanical properties with respect to neat cross-linked epoxy system. FESEM micrographs of fractured surfaces were examined to understand the toughening mechanism.