METHOD PREPARING POLYBUTADIENE Russian patent published in 1999 - IPC

FIELD: chemistry of polymers. SUBSTANCE: method is carried out by polymerization of butadiene-1,3 in hydrocarbon solvent in the presence of n-butyl lithium, modifying additive and divinyl benzene. Polymerization is carried out by addition of butadiene in two or three steps. When adding butadiene in two steps, 70-80 wt % of butadiene is added in second stage, and process is carried out to 70-80% conversion. When adding butadiene in three steps 40-60 of butadiene is added in second stage, and process is carried out to at least 95% conversion, and remaining amount of butadiene is added in third stage. In this case, irrespective of the number of portions, 20-30 wt % is initially added from total butadiene, and process is carried out in toluent at 20-60 C in the presence of butyl lithium in amount of (1-4)•10^-3 mole/l, and also divinyl benzene which is added in one step in first stage or portionwise in stages at total divinylbenzene to lithium molar ratio of at least 0.20; modifying additive selected from group consisting of diethylene glycol dimethyl ether, sodium sodiumhydrofurfurylate, dipiperidine ethane or dimethylethylene diamine at modifying additive to lithium molar ratio in second stage of (0.2-0.4), respectively is added in second and third stages. Modifying additive is added in third stage by increasing ultimate modifying additive to lithium molar ratio to (0.5-1):1, respectively. Method makes it possible to prepare polymer with controllable vulcanometric characteristics of rubber mixes. EFFECT: high processibility properties. 7 ex, 1 tbl