ISSN:
0887-624X
Keywords:
polyisocyanate
;
asymmetric anionic polymerization
;
helix
;
optically active polymer
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The asymmetric anionic polymerization of o-, m-, and p-methylphenyl isocyanates, p-methoxyphenyl isocyanate, p-chlorophenyl isocyanate, 2,6- and 3,4-dimethylphenyl isocyanates, and 1-naphthyl isocyanate was carried out using chiral anionic initiators such as the lithium salts of (-) -menthol, (-) -(2-methoxymethyl) pyrrolidine, and (+) -1-(2-pyrrolidinylmethyl) pyrrolidine. Although o-methylphenyl isocyanate gave an insoluble polymer and 2,6-dimethylphenyl isocyanate afforded no polymer, the other monomers gave soluble polymers, which showed optical activity due to the prevailing helicity of the polymer chain induced by chiral initiator residues attached to the α-end of the polymer chain. The molecular mechanics conformational calculation for a tetramer of m-methylphenyl isocyanate supported the helical conformation of the main chain. The optical rotation of the polymers depended significantly on temperature. © 1994 John Wiley & Sons, Inc.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pola.1994.080320212
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