Optically clear pressure sensitive adhesives with multiple hydrogen bond cross-linking

Optically transparent pressure-sensitive adhesives (PSAs) present several challenges. Conventional PSAs typically improve cohesive strength through chemical crosslinking; however, this approach not only reduces adhesion but also diminishes light transmittance. In this study, we explored hydrogen bonding crosslinking as a replacement for conventional chemical crosslinking and successfully synthesized the crosslinker UPyHCBA, which contains UPy units capable of forming self-complementary dimers through quadruple hydrogen bonds. A transparent acrylic PSAs incorporating the UPyHCBA monomer was then synthesized via solution polymerization. By modifying the ratio of UPyHCBA, we thoroughly investigated the impact of multiple hydrogen bonds on the molecular weight distribution, adhesive properties, thermal properties, light transmission, rheological behavior, and photoluminescence spectral properties of a specific optically transparent pressure-sensitive adhesive (PSAs).