Development of Novel Triazine-Based Poly(phenylene sulfide)s with High Refractive Index and Low Birefringence

[Image: see text] High-refractive-index (high-n) polymers with a high optical transparency and low birefringence (Δn) have been desired in progressive optoelectronic devices. However, the trade-off between high-n and low-Δn remains a challenge at present. Here, the development of a novel array of high-n, high-sulfur-containing, highly transparent, colorless poly(phenylene sulfide) (PPS) polymers bearing triazine units in the main chains is reported. Six new triazine monomers T1–T6 with various pendant groups via different linkers (−O– and −NH−) could be prepared for developing PPSs with high-n and low Δn values. These PPSs (P1–P6) were obtained by the polycondensation of T1–T6 with commercial aromatic dithiol, 4,4′-thiobisbenzenethiol, respectively, which showed very high-n values (n(av): 1.6902–1.7169 at 633 nm), high optical transparency (T % > 90% @ 400 nm), and low birefringence (Δn = 0.0015–0.0042). All the PPSs displayed high n(∞) values (1.6340–1.6654), providing valuable information for the development of high-n triazine-based PPS materials for application not only in the visible region but also in the near-infrared region.