Alrstraet--~3C-NMR spectroscopy has been used for examination of 2-cyano-2-propyl end-groups in copolymers of styrene (STY) with methacrylonitrile (MAN) and with vinyl acetate (VAC) prepared at 10@' using as initiator 2-cyano-2-propylazoformamide enriched in its methyl groups with carbon-13. It is d
Reactivities of monomers toward the 2-cyano-2-propyl radical by NMR study of end groups in copolymers
β Scribed by Bevington, J. C. ;Huckerby, T. N. ;Hutton, N. W. E.
- Book ID
- 105334019
- Publisher
- John Wiley and Sons
- Year
- 1982
- Weight
- 335 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0360-6376
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β¦ Synopsis
Abstract
Copolymerizations of styrene (S) with methyl methacrylate (MMA) and methacrylonitrile (MAN) at 60Β°C were performed with azoisobutyronitrile as initiator, enriched in its methyl groups with ^13^C. From the NMR spectrum of a copolymer it is possible to compare the numbers of initiator fragments attached to the two types of monomer unit; this information can be used to study the competition between the monomers for capture of the radicals formed from the initiator. The velocity constants for addition of the 2βcyanoβ2βpropyl radical to S, MMA, and MAN are in the proportions 1:0.56:0.34; it is concluded that polar effects are of some importance in the reactions of the radical.
π SIMILAR VOLUMES
The reactivity of 2(2-hydroxy-5-vinyl)2H-benzotriazole (2H5V) structural units in a copolymer with methyl methacrylate (MMA) with respect to alkyl or peroxy radicals in the solid phase was studied. Alkyl radicals were generated through mechanical degradation of the copolymer and peroxy radicals were
Absolute rate constants for the addition of the highly nucleophilic 2-hydroxy-2-propyl radical to eight fast-reacting 1and 1,l-disubstituted alkenes in MeOH at room temperature have been determined by laser flash photolysis. Also the absorption spectra of the 2-hydroxy-2-propyl and the benzylic and