Electrical Properties of Precipitated Lignins from Different Black Liquors

Abstract Some corelations over the structure and dielectric properties of precipitated lignins from different waste black liquors of various modified soda and kraft pulping of bagasse have been discussed. The dielectric and the electrical properties at the same temperatures and frequencies ranges for the tested samples showed some differences which seems to be attributed to the difference in the structure and intermolecular interaction between lignin molecules. These differences are discussed on the basis of the molecular structure obtained from the infrared spectra. The conduction mechanism in the case of kraft and kraft sulfite lignins is due to electron transfer from the valence band to the conduction band by thermal activation.