Process for the selective polymerisation of butadiene from C4 fractions

摘要

The invention relates to a process for the polymerisation of 1,3-butadiene using the C4 fraction obtained from the pyrolysis of crude oil by means of stable, soluble lithium initiators, where the polymerisation of the butadiene is carried out from the mixture without prior removal of the other constituents of the C4 cut (1-butene, cis- and trans-2-butene, n- and i-butane, i-butene) and without incorporation thereof into the polymer. It has been found that butadiene can be converted selectively into polybutadienes and into copolymers on addition of suitable anionically polymerisable monomers. The molecular weights can be adjusted in a targeted manner. Addition of suitable agents allows products containing terminal functional groups to be prepared.