ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The NMR spectra of methyl methacrylate-styrene and methyl methacrylate-α-methylstyrene copolymers exhibit, among other features of interest, an unexpected multiplicity in the 6.4-7.8 τ region, characteristic of methoxyl protons. This multiplicity is believed due to magnetic shielding by styrene units. By comparing the results of a statistical analysis of monomer sequence probabilities with the relative areas of the methoxyl peaks, it is shown that the degree of shielding of the methoxyl protons is dependent not only upon the presence of styrene units as nearest neighbors along the chain but also upon their stereochemical configuration with respect to the methyl methacrylate units. By means of reasonable assumptions it is possible to explain the copolymer spectra and to give a partial description of the stereochemical configuration of the methyl methacrylate-styrene copolymers. The NMR method should be valuable in the analysis of other copolymers, particularly block and graft copolymers.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1962.1206217315
