PROCESS FOR PREPARING BLOCK COPOLYMERS

In the present invention there is disclosed a process for preparing block copolymers, the first block of which is formed by a nonpolar vinyl monomer and the second block is a polar vinyl monomer by two-stage anion polymerization. The invention is characterized in that in the first stage polymerization of the nonpolar vinyl monomer to a live polymer is carried out by employing an initiation complex having as initiating component an organometallic compound of the Li, Na, K, Cs alkali metal of the general formula RM, wherein R represents alkyl having 3 to 10 carbon atoms or aryl and the second component is a tertiary alkoxide of the alkali metal of the general formula ROM, wherein R represents a tertiary alkyl containing 4 to 8 carbon atoms and the molar ratio of the alkyl metal : tertiary alkoxide is within the range of 1 : 2 to 1 : 10 at a temperature ranging from -78 degC to 0 degC, and in the second stage block polymerization of the second polar vinyl monomer being initiated by the live polymer obtained in the first preparation stage takes place.