ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
An infrared study of the sulfur vulcanization process was carried out with very high cis polymers of isoprene-d8, isoprene-3-d1 and butadiene-2,3-d2 as well as the corresponding perprotio polymers. The use of deuterated polymers permitted more definitive interpretations of the spectral changes associated with vulcanization than those previously reported or were possible with the undeuterated polyisoprene or polybutadiene. It was concluded that the 10.4 μ band which develops in the spectrum of cis-polyisoprene on extended reaction with sulfur at 140°C., and which has been the subject of some controversy, arises largely from a combination of saturated ring structures, such as cyclic sulfides, and conjugated double bonds, and to a minor extent from shifted double bonds. In addition to the processes leading to these various structures, crosslinking also occurs, but it apparently produces no important changes in the spectra of the polyisoprene vulcanizate other than that associated with a decrease in the original unsaturation. Polybutadiene, in contrast to polyisoprene, undergoes extensive cis - trans isomerization when extensively vulcanized with sulfur. Apparently, ring formation and concurrent production of conjugated double bonds also occur, but there is only a very slight amount of double-bond shifting in polybutadiene.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1962.1205816666
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