Correlation between composition and adhesion properties of a zinc oxide-filled, acrylate pressure sensitive adhesive: An experimental design approach

Abstract

A Box-Behnken response surface methodology (RSM) was adopted to provide a systematic insight on the adhesion properties of an acrylate-based, pressure sensitive adhesive (PSA) filled with nano-zinc oxide (ZnO) particles as a function of its composition. In addition to the nano-filler morphologies (needle- or plate-like) and their content (0–10 per hundred resin, phr), concentrations of triethyl citrate (TEC, 30–50 phr) plasticizer and oxalic acid (OX, 0.5–1.5 phr) crosslinking agent were also changed with respect to the base polymer. Tack and peel strength properties were measured as adhesive performance characteristics. According to the results, ZnO content and its morphology played no significant role (P < 0.05) in adhesion performance of the compositions made. In contrast, the more plasticizer was used, the more peel strength and tack properties were achieved. OX showed an inverse effect on the tack and peel strength properties at a less statistically significant level. A removable PSA was achieved adopting the RSM methodology to develop formulations, which resulted in a removable and repositionable PSA. To understand these effects, molecular structures of the adhesive ingredients and their interactions were thoroughly discussed.