Interfacial Bonding Energies of Pressure Sensitive Adhesives to Substrates

Abstract

The study reports the interfacial bonding energies of pressure-sensitive adhesives (PSAs). The materials include Acrylic, PVCabro,
Polyurethane and Epoxy as single PSAs and Hybrid PSAs from the single PSAs. The substrate material was a mild steel
plate of 130mm x 130mm with 12mm thickness. The force/tack required to debond the PSA from the substrate was measured
with a universal testing machine. For determination of interfacial bonding energies between the PSA and the substrate, the
contact angle technique was used. This allowed for interfacial free energies calculation, hence the adhesive energies. The
maximum forces (tack) at maximum machine deflection, was calculated also. Epoxy PSA appears to have the greatest tack with
tack strength of 3.358E-05 N/m). This gave a stronger force required to debond or pull it out from the substrate. Acrylic PSA
gives lowest tack strength of 0.854E-5N/m, hence not the best for tough adhesive determination. Hybrid PSAs gave higher tack
than the single PSAs which is preferable for heavy-duty adhesive work. For both single and hybrid PSAs, an increase in work of
adhesion was found to lead to an increase in the bonding strength or tack strength of the adhesive. Hybridization was found to
increase the bonding strength of the resulting adhesive, on the average by about 19%. Thus valuable to those in carpentry, leather
works or composites.