2021 Volume 34 Issue 3 Pages 251-254
The polythiocyanurates with high molecular weights were successfully prepared by the phase-transfer catalyzed polycondensation of triazinedithiol with activated dibromides. These polymers were soluble in tetrahydrofuran (THF) and N-methyl-2-pyrrolidone (NMP), and readily afforded colorless and transparent cast films. The films of polythiocyanurates exhibited good thermal stabilities such as thermal decomposition temperatures of 320 ˚C in air. A relatively high glass transition temperatures of the polymers were in the range of 112-143 ˚C. The optical transmittance of the films was as high as 80% at 400 nm. The films exhibited high refractive index of 1.73 at d line, which is attributed to the triazine rings and sulfur atoms, and Abbe's number of around 18. Furthermore, the films showed the low birefringence of 0.0007-0.0022 at d-line. The obtained polymers are promising candidates for thermoplastic optical lens application.
