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Ring opening polymerization of cyclic organosilicon compounds: Recent progress
Author(s) -
Boileau Sylvie
Publication year - 1993
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19930730117
Subject(s) - organosilicon , siloxane , polymerization , polymer chemistry , toluene , polymer , ring opening polymerization , kinetics , chemistry , ring (chemistry) , cryptand , materials science , organic chemistry , ion , physics , quantum mechanics
A novel initiator, i.e. trimethylsilylmethyllithium has been successfully used for the ring opening polymerization of cyclosiloxanes in toluene, in the presence of the cryptand [211]. Suitable conditions have been found in which monomodal distributions of molecular weights of polysiloxanes are observed by GPC, even in the case of D 4 and 1,3,5,7‐tetramethyl‐1,3,5,7‐tetravinyl cyclotetra siloxane (D 4 Vi) polymerizations. Moreover, kinetics of propagation and of formation of cyclosiloxanes can be followed by 29 Si or 13 C NMR spectroscopy on living polymer solutions. The rate of propagation of hexaethylcyclotrisiloxane is 120 times lower than that of the corresponding dimethylated analog D 3 , under the same conditions.