Styrene → Styrene-butadiene-styrene

Participants

Reaction Steps

In a 2 gallon autoclave reactor, 4,500 g of cyclohexane was placed. 9 g of tetrahydrofuran, 112.5 g of styrene monomer and 1.7 g of n-butyllithium were charged into the reactor and then the reaction mixture wsa subjected to polymerization for 1 hour. Thereafter, 525 g of 1,3-butadiene monomer were injected into the reactor to polymerize for one hour. Finally, 112.5 g of styrene monomer was added and then polymerized for one hour to obtain styrene-butadiene-styrene living block copolymer with a number average molecular weight of about 50,000 which had styrene content of 30.87% (block styrene content of 30.1%) and 1,2-vinyl bond content of 41.31% (28.9% when reduced into whole polymer). Living lithium in the polymer was present in an amount of 2.00 mmol per 100 g of polymer.

Provenance & Evidence