High performance pressure sensitive adhesives by miniemulsion photopolymerization in a continuous tubular reactor

High solids content PU/(meth)acrylics latexes for application as pressure sensitive adhesives (PSAs) were successfully synthesized by miniemulsion photopolymerization in a continuous tubular reactor at room temperature. It was shown that the process is very flexible and the polymer microstructure can be widely changed by simply controlling the radical initiation using different photoinitiator types and concentrations and varying the incident light irradiance. PSAs presenting a whole spectrum adhesive properties were obtained, some of them having the desired and unusual combination of high work of adhesion and maximum shear adhesion failure temperature (SAFT > 210 °C). The adhesive properties were analyzed in terms of the molecular weight distribution of the whole sample measured by asymmetric flow field flow fractionation.