| 摘要 |
PURPOSE:To obtain a siloxane living oligomer inexpensively in good yields, by living-polymerizing a cyclic siloxane by using a sodium trialkyl silanolate as an initiator and using a specified temperature and a specified solvent. CONSTITUTION:A polysiloxane of formula III (wherein R1 is a 1-4C alkyl, R2 is methyl, ethyl or phenyl, and n is a positive integer) is obtained by living- polymerizing a cyclic siloxane of formula II (wherein R2 is as defined above and p is 3-4) at room temperature to 0 deg.C or at -40 deg.C or below in the presence of a sodium trialkyl silanolate of formula I (wherein R1 is as defined above) as an initiator in a mixed solvent comprising an ether and a hydrocarbon solvent or in an ether. As the ether, tetrahydrofuran is preferable and as the hydrocarbon solvent, hexane is preferable. It is preferable that the above reaction is carried out by using 2-3pts.vol., per pt.vol. of the ether, hydrocarbon solvent and a temperature of room temperature to 0 deg.C.
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