New Stereoregularity in the Stereospecific Polymerization of Bulky Strained Olefins: Diheterotactic Polynorbornene
| Autor: | Antonino Famulari, Lucia Zetta, Aldo Boglia, Giovanni Ricci, Stefano Valdo Meille, Antonella Caterina Boccia |
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| Rok vydání: | 2008 |
| Předmět: |
chemistry.chemical_classification
Polymers and Plastics Molecular model Organic Chemistry NORBORNENE OLIGOMERIZATION CATALYSTS Solution polymerization Polymer Crystal structure Carbon-13 NMR Catalysis Inorganic Chemistry Crystallinity chemistry Polymerization VINYLIC POLYMERIZATION Polymer chemistry Materials Chemistry MICROSTRUCTURE |
| Zdroj: | Macromolecules 41 (2008): 3109–3113. doi:10.1021/ma702769x info:cnr-pdr/source/autori:Ricci G.; Boglia A.; Boccia A. C.; Zetta L.; Famulari A.; Meille S.V./titolo:New stereoregularity in the stereospecific polymerization of Bulky strained olefins: crystalline diheterotactic polynorbornene/doi:10.1021%2Fma702769x/rivista:Macromolecules (Print)/anno:2008/pagina_da:3109/pagina_a:3113/intervallo_pagine:3109–3113/volume:41 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/ma702769x |
| Popis: | A new semicrystalline polynorbornene was obtained by stereospecific polymerization with CrCl 2 (dppa)-MAO catalyst (dppa = bis(diphenylphosphino)amine). NMR, X-ray diffraction, and modeling techniques were used, concentrating on the soluble lower molecular weight fractions, to characterize the polymer structure. The polymer presents a 2,3-exo-diheterotactic stereochemistry never observed before in the polymerization of alkenes. High symmetry, low energy chain conformations accounting for 13 C NMR data are devised. Efficient crystalline packing models consistent with powder X-ray diffraction patterns and density requirements are proposed. |
| Databáze: | OpenAIRE |
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