| 摘要 |
These polysiloxanes are modified to have side chains containing carbonate or thiocarbonate bonds; they are denoted by the formula I below, in which the various repeat units are distributed randomly. They are prepared by chemical modification of a compound II by hydrolysilylation of a compound III, and optionally grafting of the chains R5. Used as liquid crystals or supports for medications according to the definitions of Z and R5 <IMAGE> Z = residue of the molecule to be associated with the polysiloxane chain; A = -O- or -S-; E = spacing chain; R1 = lower alkyl or phenyl; R2, R3, R4 = H, lower alkyl, phenyl, R2 and R3 not denoting H simultaneously, R5 = group imparting an additional property; a+b+c>30; a NOTEQUAL 0; b and c capable of being nil; R'1, R'2 and R'3 = lower alkyl or phenyl; d+e>30; e capable of being nil, R = hydrocarbon residue containing a terminal ethylenic unsaturation.
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