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Substituent effects on the chain‐transfer behavior of 7‐methylene‐2‐methyl‐1,5‐dithiacyclooctane in the presence of disulfides and thiols
Authors:Simon Harrisson  Thomas P. Davis  Richard A. Evans  Ezio Rizzardo
Abstract:The chain‐transfer behavior of 7‐methylene‐2‐methyl‐1,5‐dithiacyclooctane was investigated in the presence of four chain‐transfer agents: thiophenol (PhSH), thiobenzoic acid (BzSH), diphenyl disulfide (PhSSPh), and dibenzoyl disulfide (BzSSBz). The chain‐transfer constants for these compounds at 60 °C were 0.38 (PhSH), 0.76 (BzSH), 0.24 (PhSSPh), and 0.05 (BzSSBz). The variations in the thiol chain‐transfer constants could be explained in terms of the stability of the resulting radicals. The chain transfer to the disulfides, however, appeared to be determined by the electronic character of the disulfide bond, and this suggests that the transfer took place via an addition–fragmentation mechanism. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4421–4425, 2002
Keywords:ring‐opening polymerization  polysulfides  kinetics (polym.)
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