Polymerization of hexaethylcyclotrisiloxane during the synthesis of carbofunctional oligo(diethylsiloxane diols)

Oligo(diethylsiloxane diols) carrying β-oxyethoxymethyl terminal groups are synthesized for the first time by the cationic polymerization of hexaethylcyclotrisiloxane in the presence of bis(β-oxyethoxymethyl)tetramethyldisiloxane with the use of sulfuric acid or the cationite KU-23 as a catalyst. It is shown that, along with oligo(diethylsiloxane diols), the products of rearrangement of diethylsiloxane chains, such as octaethylcyclotetrasiloxane and higher cycles, are formed. The reaction of dipotassium salts of oligo(diethylsiloxane diols) with chlorosilanes of the formula ClSi(CH3)2CH2O(CH2)2OCOCH3 yields acetoxy-terminated oligomers that contain octaethylcyclotetrasiloxane and higher cycles as well.