Miscibility and peel strength of acrylic pressure‐sensitive adhesives: Acrylic copolymer–tackifier resin systems

Influence of miscibility between the components in acrylic pressure‐sensitive adhesives upon their peel strength P as a function of temperature has been studied. In case of miscible blend systems, incorporation of tackifier resins into the pressure‐sensitive adhesive systems results in the modification of the bulk properties, including Tg, and a plot of P against ΔT gives a smooth master curve, where ΔT is defined as the difference between the temperature of peel test and Tg of the blend. However, in case of immiscible blends where two phases exist in the system, no master curve can be obtained, and P of an acrylic copolymer decreases as the tackifier content increases. In this case, physical properties and adhesive performance will be governed by a matrix phase, and a dispersed phase will act as a filler.