Styrene → Styrene-butadiene-styrene

Participants

Reaction Conditions

Reaction Steps

A styrene-butadiene-styrene triblock polymer was prepared using the cycloorganomagnesium initiator, IMG, as follows: To the reactor was charged 175 grams of 1,3-butadiene in 1800 grams technical hexane, followed by 4.8 mM IMG in hexane and 7.2 mM of lithium-t-butoxide in cyclohexane. The reactor was then heated to 75° C. and the reaction allowed to proceed for 4 hours. Then 226 grams of 33% styrene in hexane were added and polymerization proceeded at 90° C. for an additional hour. The reaction was then terminated by dropping the resulting polymer cement into an equal volume of isopropanol. The polymer was then isolated by precipitation after the addition of the drum-dried.

Provenance & Evidence