Effect of ring‐size in cationic polymerization of cyclosiloxanes. D6‐polymerization initiated by trifluoromethanesulfonic acid
- 1 December 1986
- journal article
- research article
- Published by Wiley in Makromolekulare Chemie. Macromolecular Symposia
- Vol. 6 (1) , 237-245
- https://doi.org/10.1002/masy.19860060122
Abstract
Cationic polymerization of dodecamethylcyclohexasiloxane (D6) initiated with triflic acid at 20°C in CH2Cl2 shows a stationary concentration of active centres. This has permitted the measurement of kpx [Pn*] for the various Dx cyclics, and of the ratios of propagation rate constants kp5/kp4 ∼ 2,2 ± 0,4 and kp6/kp4 ∼ 5,8 ± 1,2. On the other hand, the back‐biting rate constants were not significantly different for various cyclics formation (k4 ∼ k5 ∼ k6). These values have been compared with those obtained from D4 and D5 polymerizations.Keywords
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