FIELD: chemistry of polymers. SUBSTANCE: method comprises (a) preparing prepolymer by polymerization of at least one conjugated diene to obtain product comprising 1,2-disubstituted, 1,1-disubstituted, 1,1,2-trisubstituted or four- substituted olefinic double bonds in polymer; (b) epoxidizing prepolymer to form epoxy groups at substitution points, amount of functional epoxy groups in polymer being from 0.1 to 5 mequiv/g polymer and (c) contacting epoxidized polymer with alcohol having one unsubstituted hydroxy group, or with compound of general formula: MXn wherein M is selected from group consisting of hydrogen, boron, aluminium, iron and tin; X is halogen, and n is integer corresponding to valency M, or with organic complex thereof. Present invention also describes conjugated diene block copolymer containing from 0.1 to 15 mequiv hydroxy groups per g of polymer comprises alcohol groups of formula (I) or (II) wherein p is -OH-, -Cl, or OR wherein R is selected from group consisting of alkyl radicals containing up to 10 carbon atoms, groups of monohydric and dihydric alcohols; Q is - OH or -Cl provided that at least one or P or Q is -OH and R1 and R2 are hydrogen or alkyl radicals provided that if P is -OH, then only one of R1 and R2 are hydrogen. EFFECT: high degree of conversion at relatively short reaction time to readily identified product under mild conditions. 27 cl, 9 ex, 10 tbl
