Styrene → Styrene-butadiene-styrene

Participants

Reaction Steps

In a 2 gallon autoclave reactor, 4,500 g of cyclohexane was charged, followed by 9 g of tetrahydrofuran, 112.5 g of styrene monomer and 1.7 g of n-butyllithium. This mixture was subjected to polymerization for 1 hr. Then, 525 g of 1,3-butadiene monomer was added in the reactor and polymerization was carried out for 1 hr. Thereafter, 112.5 g of styrene monomer was charged and subjected to further polymerization for 1 hr, to give a styrene-butadiene-styrene block copolymer with a number average molecular weight of about 40,000 in which the styrene bond amounted to 30.4% (block styrene content 29.9%) while the 1,2-vinyl bond content of the butadiene unit amounted to 40.5%. 2.5 mmol of living lithium was found to be contained in per 100 g of the polymer.

Provenance & Evidence