Styrene → Styrene-butadiene-styrene

Participants

Reaction Conditions

Reaction Steps

A styrene-butadiene-styrene block polymer was prepared using the cycloorganomagnesium initiator, SBMG, as follows: To the reactor was charged 1.25 lbs. of 24.8% 1,3-butadiene in technical hexane and 3.1 lbs. of additional hexane, followed by 3.8 mM SBMG in styrene/hexane and 5.7 mM of lithium-t-butoxide in cyclohexane. The reactor was then heated to 60° C. and the reaction allowed to proceed for 4 hours. Then 180 grams of 33% styrene in hexane were added and polymerization proceeded for an additional hour. The coupling agent, 3.0 mM dibutyl-tin-dichloride was then added to the reactor. After one hour, the reaction was then terminated by dropping the resulting polymer cement into an equal volume of isopropanol.

Provenance & Evidence