Abstract
The lowest interfacial free energy (γ12) calculated by Fowkes' equation is considered to be one of the dominant factors so as to optimize adhesion at the interface. However, the view may not be reasonable since the lowest γ12 does not give the highest Dupre's work of adhesion (WA). In order to verify the reliability of the view, peel strength of the two kinds of pressure sensitive adhesives (PSA) to the several polyolefins including cycloolefin polymers was examined and plotted vs. the dispersion component of the surface free energy of the polyolefins (γ2d). If the view is universally reliable, peel strength must be the maximum when Y2d is equal to the dispersion component of the surface free energy of the PSA (γ1d) as well as Kitazaki's previous research. On the contrary, the obtained peel strength in our research did not show the maximum value when γ2d was equal to γ1d. According to our investigation, the lowest γ12 calculated by Fowkes' equation is not considered to be the optimum condition for adhesion at the interface.
