INS11-0615
Molecular Design of Fluorene-Derived High-Refractive-Index Polymers via Densely Packed Cardo Architectures
Topic
S11. PMSE–PSK50 Anniversary Symposium: Advancing Polymer Science for a Sustainable and Intelligent Future
When and Where
Sep 29, 2026
11:15 - 11:40
Room 110
Session Chairs
Jeong Jae WIE
Presenter(s)
Changsik Song (Sungkyunkwan University)
Co-Author(s)
Abstract
Polymeric optical materials are attractive alternatives to glass because of their low density, processability, and impact resistance, but their relatively low refractive indices and limited thermal stability remain major challenges. To address these limitations, we developed a series of fluorene-derived cardo architectures as molecular platforms for high-performance optical polymers. First, heteroatom-bridged fluorene monomers, including fluorene-xanthene (FX), fluorene-thioxanthene (FTX), and fluorene-thioxanthene-dioxide (FTXDO), were incorporated into diverse polymer backbones, affording transparent high-refractive-index materials with refractive indices up to 1.730 at 589 nm and excellent thermal properties. Building on this strategy, we further designed an oxygen-bridged dibenzofuran-cardo (DBFX) motif that combines enhanced intrinsic polarizability with efficient intermolecular packing. DBFX-based polycarbonate, polyurethane, and polyacrylate materials exhibited refractive indices of nD = 1.753–1.848, Abbe numbers of νD = 19.7–33.3, ultralow birefringence of Δn < 0.001, glass-transition temperatures of 140–240 °C, and high visible transparency. Structural and optical analyses revealed that simultaneous optimization of molar refraction and packing efficiency is key to achieving ultrahigh refractive index without sacrificing optical clarity or isotropy. These results highlight densely packed fluorene-cardo architectures as powerful design motifs for advanced optical components, coatings, and optoelectronic applications.
