In:
Macromolecular Chemistry and Physics, Wiley, Vol. 208, No. 7 ( 2007-04-03), p. 772-783
Abstract:
High‐pressure ethene polymerizations using thirteen tert ‐alkyl peroxyester initiators, RC(CH 3 ) 2 OOCOR′ (with R = methyl, ethyl, neo ‐pentyl, tert ‐butyl and R′ = methyl, i ‐propyl, propyl, butyl, tert ‐butyl, 2‐heptyl) have been carried out in a CSTR. The initiator efficiency f has been determined for each peroxyester at 2 000 bar over a range of temperatures, partly up to 250 °C. The highest initiator efficiencies, up to about f = 0.9, are observed for tert ‐butyl peroxyesters, in which the R' species is a primary radical, as e.g., with tert ‐butyl peroxypentanoate and tert ‐butyl peroxyacetate. The lowest efficiency value, of about f = 0.37, occurs with tert ‐butyl peroxypivalate. The radicals from initiator decomposition, R′COO· and RC(CH 3 ) 2 O . , may undergo β ‐scission reactions to produce R′ radicals by decarboxylation and R radicals by “deacetonization”, respectively. In‐cage termination reactions between oxygen‐centered and carbon‐centered radicals essentially control initiator efficiency. magnified image
Type of Medium:
Online Resource
ISSN:
1022-1352
,
1521-3935
DOI:
10.1002/macp.200600546
Language:
English
Publisher:
Wiley
Publication Date:
2007
detail.hit.zdb_id:
1475026-0
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