Organopolysilanes as photopolymerization initiators of polymethylvinylsiloxanes and polydimethylsiloxanes

Abstract

The organopolysilanes Me(Me2Si)nMe (n = 4–6), (Me2Si)6 and (Me3Si)2SiMePh are found to be effective photoinitiators for the polymerization of vinyl‐containing siloxane rubbers. The trisilanes Me(ME2Si)3Me and Me3SiSiMe2SiMe2Ph are slightly effective, while phenyldisilanes do not exhibit initiation activity in the process of photocuring. Polydimethylsiloxanes are cured at a slower rate under the same conditions than vinylcontaining derivatives. Two mechanisms of crosslinking are proposed: silylene–silirane–silanol and silylene–hydride–silanol.

Electroreductive Synthesis of Polysilanes, Polygermanes, and Related Polymers with Magnesium Electrodes1

“…2-Phenylnonamethyltetrasilane (6). A solution of chlorotrimethylsilane ( 1b ) (15 mmol) and 1,2-dichloro-1,1,2-trimethyl-2-phenyldisilane ( 5 ) in dry THF was electrolyzed by using the same procedure described above to give 6 in 55% yield. 6: IR (neat) 2950, 2890, 1250 cm -1 ; 1 H NMR (CDCl 3 ) δ −0.06 (s, 9H), 0.12 (s, 9H), 0.17 (s, 6H), 0.42 (s, 3H), 7.25−7.31 (m, 3H), 7.35−7.42 (m, 2H); MS m / z (relative intensity) 324 (39, M + ), 251 (60, M + − SiMe 3 ), 174 (100); HRMS calcd for C 15 H 32 Si 4 324.13810, found 324.15502.…”

Decomposition of Di-tert-butyl Peroxide in Siloxane: An Approach of the Free Radical Cross-Linking of Silicones

“…H[CH2-SiMe2-O-SiMe2-CH2]nH with n ) 2-4. 14 A solution of 1,2-bis(chlorodimethylsilyl)ethane (0.06 mol, 12.9 g) in anhydrous ether (50 mL) and chlorotrimethylsilane (0.36 mol, 39.5 g) were simultaneously added to 150 mL of distilled water in a 250 mL tricol. After stirring for 3 h, the two phases were separated.…”

“…GC/MS (m/z, intensity): 482 (1); 467 (1); 309 (12); 308 (23); 307 (71); 305 (7); 233 (23); 221 (8); 220 (11); 219 (50); 191 (7); 160 (6); 149 (13); 148 (27); 147 (100); 145 (44); 133 (6); 117 (12); 73 (67). GC/MS (m/z, intensity): 480 (8); 465 (9); 307 (19); 306 (32); 305 (100); 291 (12); 277 (10); 247 (11); 233 (31); 231 (14); 220 (10); 219 (43); 218 (16); 217 (25); 203 (10); 191 (16); 159 (9); 147 (43); 145 (67); 133 (16); 131 (11); 119 (16); 117 (31); 85 (15); 73 (96); 59 (14); 44 (31); 40 (10). Synthesis of 1,1-Dichloromethyl-1,1,3,3,3-pentamethyldisiloxane (PMS-CHCl 2).…”

Concentration fluctuation effects for dynamics of polymer solutions

“…(7) The general method for a calculation of dynamical correlation function St(q) was proposed in ref. 11. The main steps are the following.…”

“…The dynamical modulus E is governed by two main processes: (i) the "Rouse" process of redistribution o f polymer links along the tube (in order to smooth out inhomogeneities of effective polymer chain tension induced by a deformation) and (ii) a slower reptation o f chains along their tubes. The characteristic time of the first process is[11]…”