A facile post-modification strategy for carboxylic acid-functionalized UV-responsive pressure-sensitive adhesives

UV-responsive pressure-sensitive adhesives (PSAs) were achieved through the ring-opening reactions of N-carbonyl aziridine radicals. By exploiting the variable ring-opening rate (depending on the N-substituent in the aziridine ring) of a suitable monomer (N-methacryloyl-2-methylaziridine), the post-modification of the carboxylic acid-functionalized acrylic PSAs was accomplished under mild conditions. The double-bond-added PSAs were characterized by spectroscopic analysis (i.e., 1H NMR and FT-IR) and their adhesion performance was evaluated under UV light irradiation (i.e., 180° peel test and loop tack test), which confirmed their “switching-off” capabilities and real-time viscosity properties and ensured a relatively long pot life. We believe our approach will render the transformation of UV-responsive polymeric materials a feasible task, which will benefit both academic research and mass-production industry.