ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Conformational energy calculations on poly(2-vinylimidazole) (PVI) and poly (2-vinylbenzimidazole) (FBI) indicated that the syndiotactic polymer would exhibit systematic intramolecular hydrogen bonding between side groups along the chain, while the isotactic polymers could not. This fact, together with our previous wor.k using solvent effects to produce highly syndiotactic poly(methacrylic acid) during radical polymerization, indicated that similar techniques could be applied in the radical polymerization, of 2-vinylimidazole and 2-vinylbenzimidazole. These mpnomers were polymerized over a wide temperature range using cobalt 60 gamma radiation as the initiator. The conditional probabilities obtained from NMR spectra of these polymers could be fit by second order Markov statistics (FBI) and extended second order Markov statistics (PVI). The difference reflects the effect of the bulkier benzimidazole side group. The nature of the conditional probabilities needed to fit the data for PVI suggest that the stereoregularity depended on the number of consecutive terminal r placements at the end of the growing radical. A marked solvent effect was observed was attributed to the hydrogen bonding strength of the solvent and its ability to disrupt the r directing polymer hydrogen bonding.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760160515
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