A SIMPLIFIED PROCEDURE OF ANIONIC-POLYMERIZATION OF STYRENE AND DIENES USING 4,5-METHYLENEPHENANTHRENE AS AN INDICATOR

A titration method for quick and safe purification of solvents and mon omers for anionic polymerization of styrene and dienes is presented. P rotic impurities in the reaction-medium are removed by titration with butyllithium. The coloured carbanion of 4,5-methylenephenanthrene is u sed as an indicator to determine the end point of the titration. The t itration is used in the synthesis of homopolymers and block copolymers of styrene and dienes with variable 1,2-polydiene content. Homopolyme rs and block copolymers in a large range of composition, molecular wei ght and with narrow molecular weight distribution were synthetized usi ng the titration.