FIELD: polymerization processes.
SUBSTANCE: invention, in particular, relates to production of random butadiene/isoprene copolymers and consists in the following. Random butadiene/isoprene copolymer is obtained via interaction of butadiene and isoprene in presence of catalytic system. The latter is a system based on at least one conjugated diene monomer, organic phosphorus acid salt with one or more rare-earth metals, alkylation agent consisting of alkylaluminum of formula AlR3 or HAlR2, and a halogen donor represented by alkylaluminum halide. Above-mentioned salt is present in suspension of at least one inert saturated aliphatic or alicyclic hydrocarbon solvent included in said catalytic system. Molar ratio of alkylation agent to salt of one or more rare-earth metal(s) varies between 1:1 and 8:1. Reaction is conducted in inert hydrocarbon solvent or without solvent. Random butadiene/isoprene copolymer obtained according to claimed method is such in which butadiene and isoprene units are in reality randomly alternated in accordance with Bernoulli formula. Glass transition temperature TGexp of the copolymer as measured by differential enthalpimetric analysis satisfies following inequality: -0.05 = (TGexp - TGth) = 0.05, wherein TGth represents theoretic glass transition temperature of the copolymer calculated in terms of Fox equation: 1/TGth = α/ Tg(br) + β/ TG(ir), wherein Tg(br) and TG(ir) represent, respectively, glass transition temperatures measured by differential enthalpimetric analysis for polybutadiene and polyisoprene synthesized with the aid of indicated catalytic system, wherein α and β are, respectively, weight fractions of butadiene and isoprene units. Random butadiene/isoprene copolymers have elevated content of cis-1,4 bonds.
EFFECT: enabled production of copolymers, which have real random distribution of butadiene and isoprene units.
2 cl, 2 tbl
