Thermal and Spectroscopic Analyses on the Molecular Interaction Between Eucalyptus Kraft Pulp Components and Offset Printing Inks

Thermal and infrared spectroscopic analyzes were carried out in order to study the kind of interaction between the anatomical components of the bleached eucalyptus kraft pulp with offset inks. A Bauer-McNett fiber classifier was used in order to obtain the anatomical components of the pulp, separately. The determinations of the enthalpy of the processes occurring in the samples of inks and pulp, as well as the enthalpy of these components interactions were obtained by Differential Scanning Calorimetry. In the interaction between pulp and offset ink, the reduced enthalpy values of the endothermic peak were interpreted as due to the released energy for adhesion of the ink pigment to the substratum. The low enthalpy value, 58 to 121 cal.g, indicated that the settling of the ink occurs by physical interactions. The pulp fraction enriched with vessel elements caused a higher energy release during the adherence of the pigment into the pulp.