Effect of the interfacial structures of alkyl-side-chain polymer films on the peel force

Poly(ethylene-co-vinyl-n-octadecyl carbamate) (PEVODC) belongs to the general class of long alkyl side chain polymers, which are widely used as release coatings for pressure-sensitive adhesive (PSA) tapes. The physical and structural properties of PEVODC films and the mechanisms of the adhesion/abhesion processes were investigated using surface sensitive techniques. The surface free energies and the surface roughnesses of two films with different peel forces did not differ significantly. This suggests that surface free energy and surface roughness has little effect on the peel force. In contrast, sum frequency generation spectroscopy and X-ray diffraction analysis results showed that the orientation and crystallinity of the polymer that had the lower peel force were superior to those of the polymer with the higher peel force. This indicates that polymer orientation and crystallinity has a major effect on the peel force developed at the PEVODC/adhesive interface. The formation of highly ordered crystalline domains on the PEVODC surface effectively decreases the peel force. Finally, the intercalation of the polymer chains of both adhesives and release agents as well as the entanglement of polymers play critical roles in determining the adhesion/abhesion characteristics of the PEVODC coating.