Patent number: 4263401
Abstract: Thermoplastic, elastomeric polystyrene/diorganopolysiloxane block copolymers having the structural formula: ##STR1## wherein each R, which may be the same or different, is selected from the group consisting of methyl, ethyl, n-propyl, phenyl and 3,3,3-trifluoropropyl; each R', all of which are the same, is hydrogen or methyl; A is a divalent hydrocarbon radical, free of aliphatic unsaturation, having from 6 to 45 carbon atoms; each G, which may be the same or different, is a radical selected from the group consisting of those of the structural formulae: ##STR2## wherein b is 0, 1, 2 or 3, ##STR3## wherein R" is hydrogen, methyl or --Si R.sub.3, c is 0, 1 or 2 and R is as above defined; each a, all of which are the same, is 0 or 1; and n and n', which may be the same or different, represent any numbers, the sum of which is between 20 and 500, and m is any number between 1 and 1,500, are prepared by anionic "styrene" polymerization, chain extension with a vinylchlorosilane, and, ultimately, hydrosilylation.
Type:
Grant
Filed:
September 11, 1979
Date of Patent:
April 21, 1981
Assignee:
Rhone-Poulenc Industries
Inventors:
Philippe Chaumont, Jean Herz, Christian Prud'Homme