Effect of ecological treatment on adhesion of woven flax fibers in epoxy matrix

Surface treatment of woven flax fibers was investigated as means of improving their adhesion in epoxy matrix. Flax fibers were treated in two ways : (i) with enzymatic treatments using pectinase enzymes and (ii) with pectinase enzymes/detergent, respectively. For this reason, dielectric measurements were performed in the frequency range from 10^-1 Hz to 10⁶ Hz and temperature interval from 40 °C to 200 °C. Studies of dielectric relaxations in these composites revealed the presence of three relaxation processes namely the orientation polarization imputed to the presence of polar water molecules in flax fibers, the relaxation process associated with conductivity occurring as a result of the carriers charges diffusion noted for high temperature above glass transition and low frequencies, and interfacial polarization effect or Maxwell-Wagner-Sillars (MWS) relaxation that is attributable to the accumulation of charges at the flax fibers/epoxy resin interfaces. Analysis of this latter using the Havriliak-Negami model revealed that the adhesion fibers/matrix was improved by the addition of the detergent treatment to the enzymatic one.