Smectic Aggregates of Sheet-Like Side-Chain Liquid Crystalline Polyacetylenes Directly Formed During Solution Polymerization
| Autor: | Ben Zhong Tang, Lu-Mei Liu, Yuping Dong, Er-Qiang Chen, Kai-Peng Liu |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
chemistry.chemical_classification
Kinetic chain length Polymers and Plastics Organic Chemistry Solution polymerization Polymer Inorganic Chemistry Polyacetylene chemistry.chemical_compound Chain-growth polymerization chemistry Polymerization Polymer chemistry Materials Chemistry Side chain Precipitation polymerization |
| Zdroj: | Macromolecules. 43:6014-6023 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/ma100619h |
| Popis: | We have successfully synthesized two side-chain liquid crystalline polyacetylenes (denoted as P3-5 and P2-5) with the mesogenic units based on a “phenyl−ester−phenyl” motif directly linked to the semirigid polyacetylene backbone in a terminal-on mode without flexible spacer. During the polymerization catalyzed by Rh(nbd)[B(C6H5)4] in toluene, the resultant polymers (or oligomers) automatically precipitate out of the polymerization solution as red solids, which cannot be dissolved in common organic solvents. Wide-angle X-ray diffraction results confirm that the polymer precipitates possess a smectic (or sanidic) structure, suggesting that the molecules without flexible spacers are sheet-like and can stack parallel to each other during polymerization. We in situ monitored the solution polymerization and the aggregation processes using UV−visible and 1H NMR spectroscopy methods. The experimental results indicate that after reaching a critical molecular weight the P3-5 and P2-5 molecules self-aggregate in sol... |
| Databáze: | OpenAIRE |
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