9,9′‐spirobifluorene‐containing polycarbonates: Transparent polymers with high refractive index and low birefringence |
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| Authors: | Ryota Seto Takashi Sato Takahiro Kojima Katsumoto Hosokawa Yasuhito Koyama Gen‐Ichi Konishi Toshikazu Takata |
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| Affiliation: | 1. Department of Organic and Polymeric Materials, Tokyo Institute of Technology, H‐126, 2‐12‐1, Ookayama, Meguro, Tokyo 152‐8552, Japan;2. Production Engineering Research Laboratory, Canon Inc., 70‐1, Yanagi‐cho, Saiwai, Kawasaki, Kanagawa 212‐8602, Japan |
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| Abstract: | Syntheses of 2,2′‐bisalcoholic group‐substituted 9,9′‐spirobifluorene monomers 2 were performed by the reaction of 2,2′‐dihydroxy‐9,9′‐spirobifluorene 2a with haloalcohols. Polycarbonates consisting of 9,9′‐spirobifluorene skeleton in the main chain (PC 4 ) were synthesized by the polycondensation of 2,2′‐bisalcoholic monomers 2 and triphosgene or diphenyl carbonate. PC 4 showed good thermal stability: the 5% weight loss temperature was over 330 °C under both nitrogen and air atmospheres. The glass transition temperature was in a range of 16–269 °C estimated by differential scanning calorimetry, depending on the flexibility of the alkylene or oxyethylene chains of 2 . PC 4 showed high solubility toward ordinary organic solvents such as CHCl3, benzene, and THF, making possible the preparation of the flexible thin films. Very high refractive index in a range of 1.62–1.66 at 589 nm was observed although PC 4 consists only of C, H, and O atoms, whereas very low degree of birefringence was confirmed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3658–3667, 2010 |
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| Keywords: | Cardo structure 9,9′ ‐spirobifluorene low birefringence polycarbonates refractive index transparency |
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