Ring‐opening metathesis polymerization of cis‐cyanocyclooct‐4‐ene: Search for active catalysts,variation of monomer to catalyst ratios and monomer concentrations |
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Authors: | Martin F Schneider Carola Gantner Werner Obrecht Oskar Nuyken |
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Institution: | 1. Wacker‐Chair of Macromolecular Chemistry, TU München, Lichtenbergstr. 4, 85748 Garching bei München, Germany;2. Lanxess Deutschland GmbH, Business Unit TRP, Intellectual Property Strategy, Building K10, 51369 Leverkusen, Germany |
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Abstract: | The ring‐opening metathesis polymerization (ROMP) of cis‐cyanocyclooct‐4‐ene initiated by ruthenium‐based catalysts of the first, second, and third generation was studied. For the polymerization with the second generation Grubbs catalyst RuCl2(?CHPh)(H2IMes)(PCy3)] (H2IMes = N,N′‐bis(mesityl)‐4,5‐dihydroimidazol‐2‐ylidene), the critical monomer concentration at which polymerization occurs was determined, and variation of monomer to catalyst ratios was performed. For this catalyst, ROMP of cis‐cyanocyclooct‐4‐ene did not show the features of a living polymerization as Mn did not linearly increase with increasing monomer conversion. As a consequence of slow initiation rates and intramolecular polymer degradation, molar masses passed through a maximum during the course of the polymerization. With third generation ruthenium catalysts (which contain 3‐bromo or 2‐methylpyridine ligands), polymerization proceeded rapidly, and degradation reactions could not be observed. Contrary to ruthenium‐based catalysts of the second and third generation, a catalyst of the first generation was not able to polymerize cis‐cyanocyclooct‐4‐ene. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 |
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Keywords: | cis‐cyanocyclooct‐4‐ene degree of polymerization (DP) kinetics (polym ) nitrile ROMP ruthenium‐based catalysts |
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