T. Sakaguchi, T. Tsuzuki, T. Masuda
Apr 10, 2014
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0
Influential Citations
13
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Journal
Polymer
Abstract
Abstract Diphenylacetylene having a trimethylsilyl group and two methoxy groups [ p -(CH 3 ) 3 SiC 6 H 4 C CC 6 H 4 - m,p -(OCH 3 ) 2 ( 1a )] polymerized with TaCl 5 / n -Bu 4 Sn catalyst to provide a high-molecular-weight polymer ( 2a ). In contrast, monomers without trimethylsilyl group ( 1b ) and having two t -butyldimethylsiloxy groups ( 1c ) hardly polymerized because of poor solubility of the produced polymer 2b and steric hindrance of 1c . Polymer 3a with high molecular weight was obtained by desilylation of 2a using CF 3 COOH. Membranes having p,m -dihydroxyphenyl groups to certain degrees ( 4a : 40%; 4b 90%) were synthesized by cleavage of methoxy groups in the membrane of 3a using AlCl 3 . Membrane 4a showed high CO 2 permselectivity, while membrane 5a was too brittle. Polymers 2a and 3a totally dissolved in CHCl 3 and THF, and their solutions turned into gels upon addition of metal chlorides such as TaCl 5 , AlCl 3 , etc. The gels returned to solutions by adding a small amount of methanol. This indicates that 2a and 3a form non-covalent intermolecular bonds through metal–ligand interaction.