Reference

Effect of ring size in cationic polymerization of cyclosiloxanes

Effect of ring size in cationic polymerization of cyclosiloxanes. Dodecamethylcyclohexasiloxane (D6) polymerization initiated by trifluoromethanesulfonic acid. Gobin, C.; Masure, M.; Sauvet, G.; Sigwalt, P. (Univ. Pierre et Marrie Curie, Paris 75230, Fr.). Makromol. Chem., Macromol. Symp., 6, 237-45 (English) 1986. CODEN: MCMSES. DOCUMENT TYPE: Journal CA Section: 35 (Chemistry of Synthetic High Polymers) The ratios of propagation rate consts. for decamethylcyclopentasiloxane (I) [541-02-6] and dodecamethylcyclohexasiloxane (II) [540-97-6] to octamethylcyclotetrasiloxane (III) [556-67-2] were 2.2 and 5.8, resp., as detd. from cationic polymn. of the cyclosiloxanes initiated by triflic acid (IV) [1493-13-6] at 20° in CH2Cl2. The active site concn. was const. 1493-13-6 and 556-67-2 which are cas registry numbers of chemicals are mentioned. in the polymn. of II and was dependent on IV concn. to the 2.7th power. The ratios of back-biting rate consts. for I/III and II/III were 1.2 and 0.9, resp. .

Nature of active centers during anionic cyclosiloxane polymerization in bulk and in an acetone solution

Nature of active centers during anionic cyclosiloxane polymerization in bulk and in an acetone solution. Pchelintsev, V. V.; Yuzhelevskii, Yu. A.; Kagan, E. G. (Vses. Nauchno-Issled. Inst. Sint. Kauch., Leningrad, USSR). Issled. Obl. Fiz. Khim. Kauch. Rezin, 99-102. Edited by: Lepilin, V. N.; Smirnov, N. I.; Reikhsfel'd, V. O. Leningr. Tekhnol. Inst. im. Lensoveta: Leningrad, USSR. (Russian) 1975. CODEN: 37LUA3. DOCUMENT TYPE: Conference CA Section: 35 (Synthetic High Polymers) Comparison of the rate consts. of polymn. of octamethylcyclotetrasiloxane [556-67-2] and decamethylcyclopentasiloxane [541-02-6] in acetone solns. and in bulk initiated by K and Na siloxanediolates with elec. cond. of the corresponding solns. indicated anionic polymn. proceeding via free ions in Me2CO, and by ion pair active centers, rather than free ions, in bulk polymn.