PROCESS FOR THE PREPARATION OF HYDROXYL-FUNCTIONALIZED POLYETHERPOLYSILOXANE BLOCK COPOLYMERS

摘要

The present invention is directed to a hydroxyl-functionalized polyether-polysiloxane block copolymer of the structure A(-X-B)n wherein: A represents said polysiloxane block; B represents said polyether block; X is a linker group characterized by including the moiety Si-C-C- of which said Si is the terminal silicon atom of the polysiloxane block A; and, n is an integer of from 2 to 4, said block copolymer being further characterized by a terminal unsaturation of less than 0.04 meq/g, preferably less than 0.03 meq/g and more preferably less than 0.025 meq/g and the method for producing thereof.