We report on the preparation of ultrahigh refractive index polymers via the inverse vulcanization of elemental sulfur, selenium, and 1,3-diisopropenylbenzene for use as novel transmissive materials for mid-infrared (IR) imaging applications. Poly(sulfur--selenium--(1,3-diisopropenylbenzene)) (poly(S--Se--DIB) terpolymer materials from this process exhibit the highest refractive index of any synthetic polymer ( > 2.0) and excellent IR transparency, which can be directly tuned by terpolymer composition.
View Article and Find Full Text PDFThe synthesis of a novel high sulfur content material possessing improved thermomechanical properties is reported via the inverse vulcanization of elemental sulfur (S) and 1,3,5-triisopropenylbenzene (TIB). A key feature of this system was the ability to afford highly cross-linked, thermosetting materials, where the use of TIB as a comonomer enabled facile control of the network structure and dramatically improved the glass transition temperature (relative to our earlier sulfur copolymers) of poly(sulfur-random-(1,3,5-triisopropenylbenzene)) (poly(S--TIB)) materials over a range from = 68 to 130 °C. This approach allowed for the incorporation of a high content of sulfur-sulfur (S-S) units in the copolymer that enabled thermomechanical scission of these dynamic covalent bonds and thermal reprocessing of the material, which we confirmed via dynamic rheological characterization.
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