Chain transfer in the sulfur-centered free radical ring-opening polymerization of 3-methylene-6-methyl-1,5-dithiacyclooctane

Simon Harrisson, Thomas P. Davis, Richard A. Evans, Ezio Rizzardo

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25 Citations (Scopus)

Abstract

3-Methylene-6-methyl-1,5-dithiacyclooctane (MDTO, 1) was polymerized in both the presence and absence of a number of chain transfer agents, viz. 1-butanethiol (BuSH), dibutyl disulfide (BuSSBu), and dibutyl sulfide (BuSBu). Mark-Houwink-Sakurada (MHS) constants for poly(MDTO) were found to be K = 23 × 10-5 dL g-1 and α = 0.67. Using these parameters, chain transfer constants were obtained at 60°C and are reported as 0.13 (BuSH), 0.19 (BuSSBu), and 0.0025 (BuSBu). These values are compared to the corresponding chain transfer constants obtained for styrene (STY) and methyl methacrylate (MMA). Subsequently, the chain transfer activity was measured over a range of temperatures (40-80°C), and Arrhenius parameters were determined. Significant differences in chain transfer to monomer was determined across the range of temperatures 40-100°C, yielding a value for CM of 55 × 10-4 at 60°C. The likely extent of transfer to polymer in MDTO polymerizations was estimated using a model compound, 3-butylthio-2-butylthiomethyl-1-propylene (BTMP, 2), yielding an estimated value for CP of 0.35 at 60°C.

Original languageEnglish
Pages (from-to)9553-9560
Number of pages8
JournalMacromolecules
Volume33
Issue number26
DOIs
Publication statusPublished - 26 Dec 2000
Externally publishedYes

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