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

Abstract

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.

Transparent, Ultrahigh-Refractive Index Polymer Film (n ∼1.97) with Minimal Birefringence (Δn <0.0010)

“…Given the trade-off between RI and Abbe’s number, this indicates a surprisingly low optical dispersion given the extremely high RI. , The birefringence (Δ n ) of the pSDVB-sCVD, obtained by calculating the difference between the in plane ( n TE ) and out of plane ( n TM ) RI at 632.8 nm measured using a prism coupler, was quite minimal0.0010 (Figures c and S4 in Supporting Information), which is among the lower in HRIPs reported to date (Table ). , In polymers containing aromatic groups, birefringence is closely related to the anisotropy in the orientation of aromatic rings, where low anisotropy of pSDVB-sCVD leads to low birefringence . In contrast, pSDVB-IV exhibited a higher Δ n value of 0.0070 than that of pSDVB-sCVD (Figure S3a in Supporting Information).…”

Sulfur Containing High Refractive Index Poly(arylene Thioether)s and Poly(arylene Ether)s

“…Usually, sulfur containing electron rich polymers exhibit absorbance in the visible spectrum due to the presence of charge transfer interactions. 54 However, the synthesized polymers in this work show high transparency above 400 nm. The solutions of linear polymers, i.e., for 4a−f exhibited high transparency in the visible region, with no detectable absorbance in the region of 440−760 nm as shown in Figure 10.…”

Synthesis of colorless and high-refractive-index sulfoxide-containing polymers by the oxidation of poly(phenylene sulfide) derivatives

“…22 In addition, Higashihara, Ueda and co-workers reported a series of triazinesubstituted PPSs with aromatic pendants with high RI, good transparency, and small birefringence owing to the suppression of charge-transfer (CT) interactions between the electron-poor triazine and the electron-rich PPS moieties. 23 In the case of PPS derivatives, they exhibited a relatively high RI compared with other HRIPs (generally n ∼ 1.7) owing to the compact structure of the phenylenesulfide unit with small side chains, which might be derived from the strong π-π interactions inherent in the pristine PPS even with the amorphous nature. 15 However, visible coloration was inevitable in the bulk state especially in the case of a film with a large thickness.…”