High Refractive Index Copolymers from Aromatic Heterocycle‐Based Vinyl Sulfides and Phthalimide/Maleimide Derivatives

Abstract

Herein, we present the rational design and facile synthesis of high‐refractive‐index copolymers with good optical transparency and tunable thermal stability using aromatic heterocycle‐based vinyl sulfides via conventional radical copolymerization. 2‐Thiazolylvinylsulfide (2TVS), 1,3,4‐thiadiazolylvinylsulfide (1,3,4‐TVS), 3‐methylimidazolylvinylsulfide (3MIVS), and 5‐methlthio‐1,3,4‐thiadiazolylvinylsulfide (MeSTVS) were selected to enhance the refractive index, and N‐vinylphthalimide (NVPI) and N‐phenylmaleimide (NPMI) were chosen as comonomers to achieve improved transparency and thermal stability while maintaining the refractive index. The sulfur, ‐C = N‐, and imide contents in the copolymers were varied by adjusting the monomer structures and their compositions, and their effects on the refractive index, Abbe number, and optical and thermal properties were investigated. The MeTVS monomer in poly(MeSTVS) and poly(MeSTVS‐co‐NVPI) contained three sulfur atoms and two ‐C = N‐ units; consequently, these polymers exhibited excellent refractive indices in the 1.7139–1.6567 range at 589 nm, Abbe numbers between 19.1–29.1, good transparency (>90% at 400 nm), and tunable thermal properties (Tg = 49–138 °C, Td10 = 244–268 °C). Optically transparent poly(1,3,4‐TVS‐co‐NVPI) films (> 95% at 400 nm) with improved thermal stability (Tg = 89–175 °C, Td10 = 251–301 °C) were obtained, while maintaining a relatively high refractive index (1.6662–1.6752).This article is protected by copyright. All rights reserved

Polyester Platform with High Refractive Indices and Closed-Loop Recyclability from CO2, 1,3-Butadiene, and Thiols

“…It should be pointed out that the high n d and excellent transparency of polyesters are superior to most high n d materials in recent research (Figure S92). − The remaining unconjugated double bonds in the polyesters provide a convenient postmodification protocol. After a facile 2 min UV treatment of the solution of 2e , 1,2-ethanedithiol, and photoinitiator, the colorless UV-cured network with a high n d up to 1.67 and excellent transparency of 98% is obtained (Figures C, S93, and S94).…”