Effect of ligand backbone substituents of nickel α‐diimine complexes on livingness/controllability of olefin polymerization: Competition between monomer isomerization and propagation |
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Authors: | Anatolij Sokolohorskyj Robert Mundil Albena Lederer Jan Merna |
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Institution: | 1. Department of Polymers, University of Chemistry and Technology Prague, Prague, Czech Republic;2. Leibniz Institute of Polymer Research, Dresden, Germany |
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Abstract: | Four α‐diimine nickel complexes (Ar? N?C(R)? C(R)?N? Ar)NiBr2; R?H, CH3, cyclohexane‐1,2‐diyl, naphthalene‐1,8‐diyl, Ar?2,6‐i‐Pr2‐C6H3‐) were investigated in propene and hex‐1‐ene polymerization to identify the limits of backbone substituent R size needed to provide living/controlled α‐olefins polymerization by the sufficient suppression of β–H elimination transfer. Propagation kinetics measurements, molar mass on monomer conversion dependencies and reinitiation tests were used to evaluate the livingness of hex‐1‐ene polymerization. Interestingly, living/controlled hex‐1‐ene polymerization was observed in the case of all diimine derivatives including the one bearing only hydrogen atom in backbone positions. Unexpectedly, in the case of catalysts bearing H and CH3 backbone substituents, we observed the unusual isomerization of hex‐1‐ene into internal hexenes in parallel with its polymerization. Nevertheless, by subtracting the amount of monomer consumed in isomerization side reaction, polymerization still keeps the features of living/controlled process. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3193–3202 |
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Keywords: | isomerization kinetics living/controlled polymerization nickel olefin |
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