Preparation and characterization of toughened composites of epoxy/poly(3,4-ethylenedioxythiophene) nanotube: thermal, mechanical and electrical properties

This study is focused on the preparation of conductive epoxy composites and studying the effect of poly(3,4-ethylenedioxythiophene) nanotube (PEDOT) on toughening mechanical and thermal characteristics of the epoxy polymer. Composites are prepared by dispersing PEDOT in diglycidyl ether of bisphenol A (DGEBA) and, subsequently, cross-linking by using 4,4′-diaminodiphenylmethane (DDM) as curing agent. The prepared epoxy/PEDOT composites were characterized by calorimetry, mechanical, thermo-mechanical, electrical and thermogravimetry studies. Because of the higher value of the tensile strength and Tg, it is recognized that the optimum behavior of the three-component system corresponds to the 1% loading level of PEDOT. At concentrations of greater than 1% PEDOT, an adverse effect was observed on proper properties of toughened epoxy composites. The SEM observations showed growth of aggregates at high concentrations of PEDOT which lead to undesirable thermal and mechanical properties. Further, addition of PEDOT into the epoxy matrix showed an increase in electrical conductivity (EC) owing to the introduction of PEDOT as conducting and reinforcing phase.