The mechanism of action of crosslinking additives in polyethylene vulcanisation: an EPR investigation

The mechanism of action of crosslinking additives in polyethylene vulcanisation: an EPR... The nature and kinetics of the free radicals intermediates in the peroxide induced thermal vulcanisation of low density polyethylene and the mechanism of action of two crosslinking co-agents with the structure of alkenyl aromatic hydrocarbons have been elucidated by EPR spectroscopy. At low peroxide concentration, the crosslinking mechanism in the pure low density polyethylene (LDPE) matrix is based, as expected, on the H abstraction from the chains and the coupling of the resulting macroalkyl radicals. The latter reaction takes place in competition with the disproportionation causing the formation of chain unsaturations that accumulate with the reaction time. At relatively large (>2%) peroxide concentrations, such unsaturations reach high enough levels to scavenge all the initiating and macroalkyl radicals giving macroallyl radicals as the dominant intermediates and determining changes in the structure of the crosslinks during the course of the reaction. At the concentration used, the activities of the co-agents 1,3-diisopropenylbenzene and 2,4-diphenyl-4-methyl-1-pentene are sufficient to scavenge all the initiating and macroalkyl radicals by double bond addition; this mechanism, when involving macroalkyl radicals, leads to the attachment of saturated and unsaturated pendants on the LDPE chains respectively. The unsaturated pendants are thought to be responsible for the crosslinking promotion effect by the 1,3 diisopropenylbenzene coagent. The lack of the second unsaturation causes 2,4-diphenyl-4-methyl-1-pentene to act essentially as a mild antiscorch agent. Research on Chemical Intermediates Springer Journals

The mechanism of action of crosslinking additives in polyethylene vulcanisation: an EPR investigation

Loading next page...
Brill Academic Publishers
Copyright © 2002 by VSP 2002
Chemistry; Inorganic Chemistry; Physical Chemistry
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial