METHOD FOR PRODUCING SILOXANE BLOCK COPOLYMERS Russian patent published in 2017 - IPC C08G77/44 C08G77/06 

FIELD: chemistry.

SUBSTANCE: method is proposed comprising hydrolytic polycondensation of a linear oligodiorganosiloxane with chlorosilane in the presence of a hydrogen chloride acceptor, which is carried out in non-aqueous media. Oligomer Cl_aR_3-aSi-[OSi(CH₃)₂]_n-OSiR_3-aCl_a, where R=CH₃, C₆H₅, a=2-3, n=20-200 is used a the linear oligodiorganosiloxane, compound R'_4-kSiCl_k, where R'=CH₃, C₆H₅, k=3-4 is used as the chlorosilane, and a mixture of carbamide and acetone in an amount of 1.5-2.0 and 2.0-3.0 mol, respectively, for 1.0 mole of groups ≡Si-Cl is used as the hydrogen chloride acceptor. The molar ratio of oligodiorganosiloxane:chlorosilane is 1:(3-50). The resulting block copolymers can be used as a basis for polymer composite materials for various purposes, including adhesives, anticorrosion coatings, sealing and casting compositions.

EFFECT: proposed method is more technologically advanced than the existing analogs, it allows to reduce the amount of waste and improve environmental safety.

4 cl, 1 dwg, 1 tbl, 5 ex