Isoprene → HCID 19842620, compound

Participants

Reaction Steps

To form the second block, 50 ml of isoprene were added to the reaction mixture, whose contaminants had not been deactivated by an excess of initiator, and polymerization was effected at 50°C until all the isoprene had been used up. Subsequently 10 ml of styrene was pretreated with an anionic initiator (secondary butyl lithium), until the colour just turned yellow, and the so treated styrene introduced into the reactor. After all styrene has been polymerized, the reaction product was stabilized and coagulated and worked up in a conventional manner. The styrene-isoprene-styrene block copolymer formed in this way had a number average molecular weight of 36,000 - 136,000 - 36,000 for the blocks A--B--C.

Provenance & Evidence