The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 14, 1981
Filed:
Feb. 15, 1979
Nikolai S Nametkin, Moscow, SU;
Sergei G Durgarian, Moscow, SU;
Eduard G Novitsky, Moscow, SU;
Valentina G Filippova, Moscow, SU;
Natalya K Gladkova, Moscow, SU;
Vladimir V Teplyakov, Moscow, SU;
Other;
Abstract
Block-copolymers of vinyltrialkylsilane-hexaorganocyclotrisiloxane of the formula: ##STR1## wherein R, R' are the same or different and each R.sub.3 represent methyl, phenyl; R.sub.1, R.sub.2, R.sub.3 --are each an aliphatic radical containing 1 to 4 carbon atoms, Z is a residue of a dilithium initiator of polymerization of a vinyltrialkylsilane K is a residue of a monolithium initiator, which is a hydrocarbon radical- normal or iso-alkyl; K' is hydrogen, an (R.sub.3) Si silcarbonic group wherein R is a C.sub.1 -C.sub.4 alkyl radical, or a hydrocarbon radical; a=0 to 10.sup.4 ; b=0 to 10.sup.4 ; C=10 to 10.sup.4 ; d=10 to 10.sup.4 ; f=0 to 1; g=0 to 1, x.gtoreq.1, with a molecular mass of from 10.sup.3 to 10.sup.6. A method for preparing these block-copolymers comprises polymerization of vinyltrialkylsilanes in the presence of mono- or dilithiumorganic initiators, whereafter a solution of a hexaorganocyclotrisiloxane is added to the reaction mixture and polymerization is effected to give intermediate block-copolymers, whereafter the polymerization is stopped or the intermediate block-copolymers are combined by means of a cross-linking agent, followed by recovery of the desired product. The block-copolymers according to the present invention feature a high selectivity of permeation for certain gases. Thus, the ratio of permeability constants for oxygen and nitrogen (P.sub.O.sbsb.2 /P.sub.N.sbsb.2) is as high as 3.5. At the same time, the absolute value of gas-permeability constants is also high, i.e. P.sub.O.sbsb.2 is as high as 1.4.times.10.sup.-8 cm.sup.3.cm/cm.sup.2 cm Hg.sec.