Synthesis and some properties of functional linear and cyclic polyethylsiloxanes

1. The stepwise condensation of ethylchlorosilane with diethylsilanediol and 1,3-dihy-droxytetraethyldisiloxane was used to obtain 2,6- and 2,8-dichloroethylcyclotetra (penta, hexa) siloxanes. It was established that the reaction is accompanied by intramolecular cyclization in the reaction with 1,3-dihydroxytetraethyldisiloxane: in the first step with the formation of chloropentaethylcyclotrisiloxane and in the second step with the formation of 2,8-dichlorodecaethylcyclohexasiloxane and its structural isomer. 2. An increased tendency to form ethylbicyclo [3.5.1]penta- and ethylbicyclo[5.5.1]-hexasiloxane was observed in the hydrolysis of 2,6-dichlorooctaethylcyclopenta- and 2,8-dichlorodecaethylcyclohexasiloxanes.