Free radical initiation mechanisms in the polymerisation of diethyl fumarate and diethyl maleate studied by the nitroxide trapping technique

✍ Scribed by W. Ken Busfield; Ian D. Jenkins; Kirstin Heiland

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 580 KB
• Volume: 30
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(94)90136-8

✦ Synopsis

The radical trapping technique employing the stable nitroxide 1 as a scavenger has been used to study the reaction of t-butoxyl radicals with diethyl fumarate and with diethyl maleate. The major pathway with both monomers is hydrogen abstraction from the ester alkyl groups by t-butoxyl radicals. The addition of t-butoxyl radicals to monomer is of minor importance. At low nitroxide concentrations, addition of the secondary hydrogen abstraction radical to monomer is competitive with trapping by the nitroxide. This suggests that the initial propagation rate constant is much greater than the overall average propagation rate constant for homopolymerisation of these monomers.