Changes in free surface energy as an indicator of polymer blend miscibility

Changes in free surface energy as a result of differences in polymer blend miscibility were investigated. When high density polyethylene (HDPE) and a hard Fischer–Tropsch paraffin wax are miscible, the total surface energy of the blend decreases compared to that of the pure polymer, and the polar part of the surface energy increases. At higher wax contents, the miscibility with HDPE is lower, and this is accompanied by a decrease in the polar part of the surface energy and an increase in the total surface energy. Differential scanning calorimetry was used to monitor the miscibility, and the determination of the surface energy was carried out on a surface energy evaluation system (SEES), which enables the calculation of the surface energy on the basis of the most often used models.