Synthesis and mechanical properties evaluatioin of waterborne PSA'S with core-shell morphology

In this work, a series of Pressure Sensitive Adhesives (PSAs) of poly(n-butyl acrylate-2-ethyl hexyl acrylate-acrylic acid) were synthesized via emulsion polymerization. The PSAs particles were carried out in a semicontinuous process. Synthesis was carried out in two stages of thereaction. In the first, a core of poly(butyl acrylate-co-2-ethyl hexyl acrylate) with a composition of 50/50 wt%/wt % was synthesized, while in the second stage, the core was charged in the reactor as a seed; and was recovered with a poly(butyl acrylate-co-2-ethyl hexyl acrylate-coacrylic acid) shell. The acrylic acid in the shell was varied between 0, 1, 3 and 5 wt%. The PSAs obtained were characterized by dynamic light scattering and zeta potential. The results of dynamic light scattering showed monodispersed particles with an average particle size of 350 nm, while the zeta potential results decreased as the acrylic acid content increased. The mechanical tests showed that the increase in acrylic acid content in the particle shell improves the adhesion properties. For peel adhesion, the maximum value was reached at 3 wt% of acrylic acid.