Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5189510 | Polymer | 2006 | 11 Pages |
Abstract
EPR spectroscopy has been employed to detect directly radicals formed from a variety of polyolefins (PE, PP and EPM) during reaction with peroxide-derived alkoxyl radicals generated by thermolysis. Conditions have been chosen to reflect those employed in polyolefin grafting, degradation and cross-linking. Radical assignment is assisted, in particular, by the recognition of the effects of chirality on the β-proton hyperfine splittings. Quantitative analysis provides information on the selectivity of the initial attack (e.g. methine protons>methylene protons for PP); notable differences in selectivity between alternating EPM and other EPM samples are discussed. The detection of longer-lived allyl radicals detected for PE is explained in terms of alkyl radical disproportionation with subsequent reaction of the product alkene.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Susana Camara, Bruce C. Gilbert, Robert J. Meier, Martin van Duin, Adrian C. Whitwood,