Experimental study of relaxation process in unidirectional (epoxy/palm tree fiber) composite

New structural composite material reinforced with unidirectional natural fibers is prepared. Investigation on the dielectric properties and behavior of the thermoset epoxy composite based on cellulosic fibers has been carried on. For the composite, tree relaxation processes were identified, namely the a mode relaxation associated with the glass transition of the epoxy resin matrix, the relaxation process associated with conductivity occurring as a result of the carrier charges diffusion noted for high temperature above glass transition and low frequencies, and interfacial or Maxwell-Wagner-Sillars relaxation that is attributable to the accumulation of charges at the palm tree fibers/epoxy resin interfaces. (C) 2010 Elsevier B.V. All rights reserved.