Some Effects of Corona Plasma Treatment of Polylactide/Montmorillonite Nanocomposite Films

Influence of the unit energy ( E u ) of corona discharge used for modification of pure polylactide (PLA) and polylactide nanocomposite (PLAC) containing 5 wt% of an aluminosilicate nanofiller (Cloisite 30B) on water (Θ W ) and diiodomethane (Θ D ) contact angles as well as on surface free energy ( γ s ) of these polymers was studied. Θ W and Θ D as advancing contact angles were measured with use of a goniometer while γ s was calculated by the Owens–Wendt method. It was found that Θ W increased with the rising E u while Θ D remained approximately constant. Assuming E u  = const, it could be stated that the increase in γ s was much more evident for PLA than for PLAC. This increase resulted practically from the change in the polar component of γ s because the dispersive component for the two materials only slightly decreased with increase in E u .