Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9817875 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2005 | 7 Pages |
Abstract
The experimental low-temperature EPR results and the quantum chemical calculations suggest that dimer radical cations of cyclic and aliphatic vinyl ethers (VE) plays a key role in starting of radiation-induced polymerisation. The main species observed at high 2,3-dihydrofuran (DHF), 2,3-dihydropyran (DHP) and VE concentration is the dimer radical cation. In the case of cyclic VE the dimer radical cation transforms through H-abstraction from neutral molecule into a carbocation and radical, which could start both cationic and free-radical polymerisation. However, in the case of aliphatic VE no further reactive species, which could start polymerisation, were observed. This is caused (in agreement with experiment and quantum chemical calculations) by the very high stability of dimer radical cation and calculated endothermity of H-abstraction reaction by dimer radical cation from monomer.
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Authors
Sergej Naumov, Igor Janovský, Wolfgang Knolle, Reiner Mehnert,