Randomly Distributed Sulfur Atoms in the Main Chains of CO 2 ‐Based Polycarbonates: Enhanced Optical Properties
| Autor: | Wei-Min Ren, Xiao-Bing Lu, Tian-Jun Yue, Wen-Jian Zhang, Donald J. Darensbourg, Bai-Hao Ren |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
Materials science 010405 organic chemistry Abbe number General Chemistry Polymer General Medicine 010402 general chemistry 01 natural sciences Catalysis 0104 chemical sciences chemistry.chemical_compound Chemical engineering chemistry visual_art visual_art.visual_art_medium Thiocarbonate Thermal stability Polycarbonate Bimetallic strip Refractive index Cyclohexene oxide |
| Zdroj: | Angewandte Chemie. 133:4361-4367 |
| ISSN: | 1521-3757 0044-8249 |
| DOI: | 10.1002/ange.202012565 |
| Popis: | Polymeric materials possessing both high refractive indices and high Abbe numbers are much in demand for the development of advanced optical devices. However, the synthesis of such functional materials is a challenge because of the trade-off between these two properties. Herein, a synthetic strategy is presented for enhancing the optical properties of CO2 -based polycarbonates by modifying the polymer's topological structure. Terpolymers with thiocarbonate and carbonate units randomly distributed in the polymers' main chain were synthesized via the terpolymerization of cyclohexene oxide with a mixture of CO2 and COS in the presence of metal catalysts, most notably a dinuclear aluminum complex. DFT calculations were employed to explain why different structural sequence were obtained with distinct bimetallic catalysts. Varying the CO2 pressure made it possible to obtain terpolymers with tunable carbonate linkages in the polymer chain. More importantly, optical property studies revealed that terpolymers with comparable thiocarbonate and carbonate units exhibited a refractive index of 1.501 with an enhanced Abbe number as high as 48.6, much higher than the corresponding polycarbonates or polythiocarbonates. Additionally, all terpolymers containing varying thiocarbonate content displayed good thermal properties with Tg >109 °C and Td >260 °C, suggesting little loss in the thermal stability compared to the polycarbonate. Hence, modification of the topological structure of the polycarbonate is an efficient method of obtaining polymeric materials with enhanced optical properties without compromising thermal performance. |
| Databáze: | OpenAIRE |
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