ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The formation of a charge-transfer complex between 1-vinylindole (1a) and maleic anhydride (MA) was detected by 1H NMR analysis, and the corresponding Keq was measured (Keq=0,251 mol in CDCl3 at 25°C). It could be shown that this complex can be involved both in the initiation and propagation steps of the 1a-MA copolymerization by carrying out spontaneous copolymerization experiments and studying the influence of the feed composition on the conversion and [η] of the copolymer. The structure of the 1a-MA copolymer, investigated by 13C NMR spectroscopy, was found to be complicated due to the formation of indoline rings along the chains by an attack of the propagating MA radical at position 2 in the indole ring. As a consequence an excess of MA, with respect to a 1:1 mole ratio of monomer feed, was usually found in the copolymer. The mechanism of the cyclization reaction was clarified by copolymerizing MA with 2-methyl-1-vinylindole (1b), 3-methyl-1-vinylindole (1c), or 2,3-dimethyl-1-vinylindole (1d). An alternating copolymer with MA (mole ratio 1:1 of monomeric units), without irregularities, was obtained only by employing 1d as a comonomer.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1979.021800102
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