Polyfunctional poly-organo-siloxane(s) - by low-temp. nitration of poly-methyl-phenyl-siloxane(s), and conversion of nitro gps. into other functional gp(s)

摘要

Polyfunctional polyoganosilanes are of formula (I) (where n = 10-500; R = Me, with ratio Me:Ph gps. = (2.2:1)-(3.5:1); X = NO2, NH2, OH, Hal, CN, NCO, (meth)acrylate gp. or maleimide gp. of formula (II) (with R1 = H, 1-4C alkyl or Ph). Also claimed is a process for the prodn. of (I) by low-temp. nitration of the corresp. unsubstd. polymer (with X = H) with a mixt. of Ac2O and concentrated HNO3 to give a poly(nitrophenyl)siloxane (I, X = nitro). Other functional gps. are introduced by redn. of the nitro polymer (pref. with Fe/AcOH in EtOH) to give the corresp. amine, and conversion of the amine gps. into OH, Hal, CN or NCO, or into maleimide gps. by reaction with opt. substd. maleic anhydride. USE/ADVANTAGE - (I) are used for prodn. of polymers with liq. crystalline side chains (claimed). Enables prodn. of polymers with the usual desirable properties of silicones (thermal stability, elasticity, low water absorption, good electrical properties, etc.) combined with functionality distributed along the whole polymer chain, which can be used to introduce mesogenic gps., etc.. Other applications include photosensitive resists, photo-crosslinkable coatings, etc..