Linkage Configurations at the Cyclic Maleic Anhydride Units and Sequence Distribution in Copolymers ofp-Chlorostyrene with Maleic Anhydride
✍ Scribed by RungAphinya, Wanna; Fujimori, Kiyohisa; Craven, Ian E.; Tucker, David J.
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 271 KB
- Volume
- 42
- Category
- Article
- ISSN
- 0959-8103
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✦ Synopsis
Semi-alternating copolymers were formed in the radical copolymerization of p-chlorostyrene (p-ClSt) with maleic anhydride (Man) in solu-CCl 4 tions at 50¡C. The triad distributions in the copolymers and the ratio of the amounts of entgegen (E) and zusammen (Z) linkage conÐgurations at the cyclic Man units in the copolymers were determined by using 13C nuclear magnetic resonance spectroscopy. The equilibrium constant of the electron donorÈ acceptor complexation of p-ClSt and Man in solution was determined to be CCl 4 0É32 ^0É03 M~1 at 23¡C. A non-linear least-square regression of the triad distribution data showed that the copolymerization models which involved complex participation were preferable, although not conclusively, to the penultimate unit model. As much as 40% of the linkages at the Man units in the semi-alternating copolymers were found to be in the Z conÐguration, strongly indicating a participation of the donorÈacceptor complex formed between p-ClSt and Man.