Polymerization of dec-1-ene—II. Product analysis shows that the free radical process is an oligomerization, and reveals mechanistic details

✍ Scribed by Derek R. Illsley; Roy S. Lehrle

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 491 KB
• Volume: 27
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(91)90219-e

✦ Synopsis

The products from the free radical polymerization of dec-l-ene have been analyzed and characterized in an effort to specify the details of what has previously (part I) been shown to be essentially a degradative chain transfer mechanism. Vapour phase osmometry and gel permeation chromatography show that the products are oligometric, and the latter technique shows an abnormally high dimer component in the distribution, a finding consistent with the mechanism proposed. NMR analysis shows the absence of groups corresponding to initiator fragments in the oligomers and, on this basis, it is proposed that initiation occurs by transfer to monomer to yield non-allylic radicals. Gas chromatographic analysis coupled with mass spectrometry has revealed the presence of four distinct "dimer" types, each in several isomeric forms:

(1) dimer monoenes resulting from the propagation reaction;

(2) dimer dienes resulting from the recombination of allylic radicals;

(3) methyl-benzyl radical recombination products; and (4) combination products resulting from interaction of a methyl-benzyl radical and an allylic radical. Detailed mechanisms for total oligomeric product formation are proposed on the basis of these results.