UV-Blocking Pressure-Sensitive Adhesives for Optoelectronic and Display Applications

With the increasing demand for advanced optoelectronic devices such as displays and optical components, pressure-sensitive adhesives (PSAs) that maintain high transparency and long-term stability under UV exposure have become increasingly important. Conventional PSAs for optoelectronic applications rely on the incorporation of UV absorbers, which leads to phase separation under prolonged UV exposure. This results in reduced adhesion performance, adhesive residue after debonding, and decreased durability due to photodegradation and yellowing.
To address these issues, a UV-absorbing fused bithiophene structure was designed in an acrylate form and introduced into a PSA system via copolymerization. The conjugated fused bithiophene as a covalently bonded UV absorber within the polymer structure, effectively suppressing phase separation. Fused bithiophene acrylate monomers with tunable photo-oxidative stability were synthesized by varying the alkyl substitution (-H or alkyl group).
The PSAs prepared via photopolymerization exhibited excellent thermal stability, mechanical properties, and rheological behavior, along with high adhesion strength (~24 N/25 mm). They also maintained high optical transmittance (>98%) in the visible region while providing effective UV-blocking capability in the 200–300 nm region.
These results suggest a new design strategy for UV-blocking adhesive materials that simultaneously achieve high transparency and durability, highlighting their strong potential for next-generation display and optoelectronic applications.