ISSN:
0887-624X
Keywords:
cyclosiloxanes
;
ring-opening polymerization
;
nonequilibrium copolymerization
;
siloxane copolymers
;
29Si NMR
;
sequence distribution
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Nonequilibrium anionic ring-opening copolymerization of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane (V4) with hexamethylcyclotrisiloxane (D3) was examined as a route to methylvinyl-dimethylsiloxane microsequential copolymers. The copolymerization was carried out in toluene and was initiated with Me3SiCH2Li using DMSO as the promoter. Distribution of siloxane units obtained from kinetic analysis based on first-order Markovian statistics was compared with that found from analysis by 29Si NMR spectroscopy. Results showed that although chain transfer and back-biting play some role in this system, the kinetics of copolymerization may be described to a reasonable approximation by the first-order Markov model. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 137-145, 1998
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
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