Designing Ultrahigh-Refractive-Index Amorphous Poly(phenylene sulfide)s Based on Dense Intermolecular Hydrogen-Bond Networks

High-refractive-index polymers (HRIPs) are currently in demand for the fabrication of state-of-the-art optical devices with high performance. However, few HRIPs that display both ultrahigh refractive index (over 1.8) and high Abbe number (over 20) have been reported owing to the typical trade-off between these two parameters. Herein, we found that poly(2-hydroxy-1,4-phenylene sulfide) exhibited an unprecedented ultrahigh refractive index (n_D= 1.80) with an amorphous nature, high glass-transition temperature, good transparency, and high Abbe number (ν_D= 20). Spectroscopic analyses and density measurements revealed that the dense hydrogen-bond (H-bond) networks of the hydroxy-substituted poly(phenylene sulfide) in the bulk state enabled the realization of an ultrahigh refractive index without any decline in transparency.