Proton magnetic resonance investigation of structure of ω-alkyl-α-olefin/SO2 copolymers

Autor: Robert Bacskai, W. A. Sweeney, L. P. Lindeman, Derek L. Ransley
Rok vydání: 1969
Předmět:
Zdroj: Journal of Polymer Science Part A-1: Polymer Chemistry. 7:247-257
ISSN: 1542-9350
0449-296X
DOI: 10.1002/pol.1969.150070121
Popis: The 100 MHz proton magnetic resonance (PMR) spectra of free radical alternating ω-alkyl-α-olefin/SO2 copolymers has been investigated. The data obtained from the quantitative evaluation of the spectra are consistent with a copolymer structure containing unrearranged olefinic monomer units. The 4-methyl-1-pentene/SO2 copolymer shows a quadruplet resonance in the CH3 proton region. This multiplicity, observed also in the analogous 1,2-dichloro-4-methylpentane and 1,2-dibromo-4-methylpentane, arises from the presence of magnetically nonequivalent CH3 protons located in the vicinity of the asymmetric carbon atoms of the main chain. There is no detectable nonequivalency of CH3 protons in the 5-methyl-1-hexene/SO2 copolymer, probably because the center of asymmetry is further removed from the isopropyl group. In poly-4-methyl-1-pentene, prepared with Ziegler-Natta catalyst, the polymer structure around the main chain tertiary carbons is fairly symmetrical; and, as expected, the CH3 protons of the isopropyl group are magnetically equivalent.
Databáze: OpenAIRE
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