A new route of synthesis of block copolymers was investigated. it involves the polymerization of a side-chain liquid-crystalline acrylate and poly(propylene glycol), modified by an esterification reaction with mercaptoacetic acid used as macrotransfer agent, in the presence of 2,2'-azoisobutyronitrile as initiator. The molecular weight of the liquid-crystalline blocks is determined by the molar ratio between the reactants.