The Polymer Society of Korea

최윤지 (울산과학기술원)

이동욱 (울산과학기술원)

Flexible and foldable displays require optically clear adhesives (OCAs) that maintain ultra-high optical transparency, stable adhesion, low modulus, and rapid recovery under repeated deformation. Conventional acrylic OCAs using rigid small molecular weight crosslinkers, such as HDDA, improve recovery but often suffer from reduced adhesion at high crosslink density. Here, a polyurethane diacrylate (PUDA) crosslinker was synthesized from an isosorbide polyol and H6XDI. Owing to its high molecular weight (44,000 g mol⁻¹), PUDA hinders the formation of new hydrogen bonds between CEA units during straining, enabling rapid elastic recovery. PUDA crosslinked OCAs exhibited ultra-high transmittance (>99.6%), low modulus, and stable adhesion. Notably, fast strain recovery was achieved within 2.5 s, together with clean debonding without residue, even at 80 °C. These results demonstrate that PUDA based OCAs are promising for flexible and foldable display applications.