Styrene → Styrene-butadiene-styrene

Participants

Reaction Steps

In a 2 gallon autoclave reactor, 4,500 g of cyclohexane was charged. 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 was subjected to polymerization for 1 hr. Then, 525 g of 1,3-butadiene was added in the reactor to polymerize for 1 hr. Thereafter, 112.5 g of styrene monomer was charged and polymerized for 1 hr, to give a styrene-butadiene-styrene block copolymer with a number average molecular weight of about 40,000 in which styrene bond amounted to 29.5% (block styrene content 29.1%) while the 1,2-vinyl content of butadiene unit amounted to 36.5%. The copolymer contained 2.5 mmol of living lithium per 100 g of the polymer.

Provenance & Evidence