Polystyrene-di:organo:polysiloxane elastomer - used for moulded goods, coatings, fibres, selectively permeable membranes and prostheses

• Main Author: PHILIPPE CHAUMONT, JEAN HERZ ET CHRISTIAN PRUD'HOMME
• Format: Patent
• Language: English; French
• Published: 10.04.1981
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

Parent patent claims thermoplastic elastomers having units of formula (-CH2CH2SiR2(C(C6H5)2-CH2)a (C(G)R'-CH2)n-A-(CH2-C(G)R')n (CH2-C(C6H5)2) SiR2CH2CH2SiR2(OSiR2)m, where R is (m)ethyl, n-propyl, phenyl or 3,3,3-trifluoropropyl; R' are H or methyl; A is a 6-45C naphthalene, biphenylene, alkylene or polyalkylene gp., opt. substd. by aromatic rings; G is (I) C6(H)5-b(CH3)b, where b is 0-3, or (II) C6H4N(CH3)2; a is 0 or 1; n and n' are 20-500; and m is 1-1500. Polystyrenic polydiorganopolysiloxanes have the above formula, in which G is C6H4R"c(SiR3), where R" is H, methyl or SiR3; and c is 0-2, are novel. The copolymers can be used for joints, profiles, insulating or protective coatings, and fibres. The gas permeability is good and the copolymers can be used for selectively permeable membranes, e.g. for artificial lungs, or for sepn. of gaseous mixts. They are physiologically inert and can be used for prostheses. In the new elastomers, some of the G gps. may be of formulae (I) or (II). The mol. wt. is 20,000-2,000,000. Pref., the copolymer contains 30-85wt.% of the siloxane units. The claimed prepn. involves (a) anionic polymerisation of C(G)R'=CH2, using AM2, where M is K, Na or Li as initiator, to give a living polymer, (b) reaction of the mixt. from (a) with diphenylethylene, to give a second living polymer, (c) reaction of the polymer from (b) with (CH2=CH)-R2SiCl, to give a polystyrenic difunctional polymer, and (d) reaction of this difunctional polymer with HSiR2(OSiR2)mH. La présente invention concerne des élastomères thermoplastiques séquencés polysiloxaniques, polystyréniques silylés. Les élastomères selon l'invention sont obtenus en polymérisant anioniquement dans une première étape un monomère styrénique silylé, en neutralisant dans une deuxième étape le polymère vivant par un vinylchlorosilane, et enfin en faisant réagir dans une troisième étape, le polystyrène alpha, oméga bisvinylsilylé avec un alpha, oméga hydrogénopolysiloxane. Les copolymères sont des élastomères thermoplastiques ayant de bonnes propriétés thermomécaniques.