FIELD: polymers, chemical technology.
SUBSTANCE: invention relates to a method for synthesis of copolymer used in rubber mixture and cross-linked with sulfur with reduced hysteresis in cross-linked state and comprising two blocks wherein one block consists of polyisoprene and another block consists of styrene-diene elastomer distinct from polyisoprene, and to a rubber mixture for tire protectors. Method for synthesis of copolymer involves co-polymerization of one or some monomers comprising coupled diene distinct from isoprene and by using catalytic system comprising at least one hydrocarbon solvent, metal compound A from the group IIIA, alkaline metal compound B and polymeric initiator C with a bond C-Li that consists of monolithiated polyisoprene designated for formation of polyisoprene block and wherein an average molecular mass Mn1 of indicated polyisoprene block is in the range between 2500 and 20000 g/mole. Method involves to preparing copolymer wherein another block consisting of indicated diene elastomer with an average molecular mass Mn2 between 65000 and 350000 g/mole and the content of trans-1,4-bonds is 70% or above. Invention provides reducing hysteresis of mixtures to limit consumption of fuel and to provide safety of environment.
EFFECT: improved method of synthesis.
22 cl, 5 tbl, 5 ex
