A stereochemical study of citraconic anhydride units in copolymers of styrene with citraconic anhydride via 13C-NMR spectroscopy

✍ Scribed by Paul G. Brown; Kiyohisa Fujimori

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 485 KB
• Volume: 30
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(94)90244-5

✦ Synopsis

The configuration of citraconic (~-methylmaleic) anhydride units in styrene/citraconic anhydride copotymers prepared in methyl ethyl ketone at 50.0 + 0. V was determined over a wide range of comonomer feed compositions using ~3C-NMR spectroscopy. It was found that the ratio of Z (zusammen) to E (entgegen) configurations of citraconic anhydride units in these copolymers increased with the degree of alternation of the comonomer units, reaching a constant value of approx. 1.3 when the comonomer units were almost completely alternating and the mole fraction of citraconic anhydride units in the copolymers approached 0.50. This result was found to be consistent with previous related work, suggesting the existence of a link between the stereoregularity and alternating tendency of comonomer units in copolymerisation systems where pairs of comonomer units can form ! :1 electron donor acceptor (EDA) complexes in the comonomer feed.