PURPOSE: To prepare a 5-hexenyl-terminated polydimethylsiloxane polymer by bringing a mixture of a specified chlorine-terminated polydiorganosiloxane polymer and an organofunctional chlorosilane end-blocker into contact with water contg. hydrogen chloride.
CONSTITUTION: A chlorine-terminated polydiorganosiloxane polymer of formula I [where R is 1-20C alkyl, 4-20C cycloalkyl or aryl; and (n) is 1-1,000] is mixed with an organofunctional chlorosilane end-blocker of formula II [where R1 is an organofunctional group selected from 2-20C alkenyl and 1-20C haloalkyl; (a) is 1-3; (b) is 0-2 and a+b=3] in a molar ratio of 0.5-10 to obtain a mixture. This mixture is brought into contact with stoichiometric excess water contg. 5-36 wt.% hydrogen chloride at 20-50°C for 0.1-18 hr and the resultant organofunctional-terminated polydiorganosiloxane polymer of formula III [where (x) is n+1 to n+1,000] is separated.
CHIYAARUZU ERUBIN NIIRU JIYUNI
DEBITSUDO ERITSUKU PAKETSUTO
RARII HAABAATO UTSUDO
