Autor: Emiel Peeters, Henk M. Janssen, M. F. van Zundert, E. W. Meijer, M.H.P. van Genderen
Rok vydání: 1996
Předmět:
Zdroj: Acta Polymerica. 47:485-491
ISSN: 1521-4044
0323-7648
Popis: A novel synthetic route to and a polymerization procedure for oxo-crown ethers 2,11-dioxo-18-crown-6(1), 2-oxo-12-crown-4 (2) and 2-oxo-21-crown-7(3) are described. Cyclization of the ω-hydroxycarboxylic acid precursors of 1-3 has been achieved by heating these precursors in the presence ofa Lewis acid catalyst (CoCl 2 ) and a template salt (MCI). Cyclization yields up to 82% were reached, using CsCl as template salt. Oxo-crown ethers 1-3 have been polymerized using SnOct 2 as catalyst, giving polymers with molecular weights of approximately 5 kg/mol and dispersities of ca. 1.8 (measured with polyethylene oxide standards). The polymerization of 2 was monitored with 'H-NMR and SEC giving information about (a) the influence of monomer/catalyst ratio and temperature on polymerization rate and (b) the influence of temperature on molecular weight (distribution). The possibility of introducing endgroups into poly(2-oxo-12-crown-4) using SnOct 2 -catalyzed polymerization was also studied.
Databáze: OpenAIRE
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