Effect of wool and thermo-binder fibers on adhesion of alfa fibers in polyester composite

Dielectric study was investigated in order to probe the interfacial region fibers/matrix of the polyester composite reinforced with alfa/wool/thermo-binder fibers. Dielectric spectra were measured in the frequency range from 10(-1) Hz to 10(6) Hz, and temperature interval from 40 degrees C to 150 degrees C. This study revealed the presence of two dielectric relaxations in the composite. While the first one was attributed to the a mode relaxation associated with the glass transition of the matrix, the second was associated with the conductivity resulting from the carriers' charges diffusion noted for high temperature above glass transition and low frequencies. As this study did not show the presence of the interfacial polarization effect in the composite, it was accomplished with the vibrational study using the FT-IR and Raman techniques. A great compatibility between fibers and matrix was proven by a less hydrophilic character of the reinforcement giving rise to additional valence vibrations from wool fibers and hydrogen bonds. (C) 2013 AIP Publishing LLC.