Styrene → Styrene-butadiene-styrene

Participants

Reaction Steps

To a 200 L pressure resistant vessel flushed with dry nitrogen, 60 kg of cyclohexane and 35 g of sec-butyl lithium as a polymerization initiator were added followed by addition of 2.9 kg of styrene. After polymerization at 50 to 52° C., 0.17 kg of THF was added and 26.2 kg of butadiene and 2.9 kg of styrene were added in order for polymerization. As a result, a styrene-butadiene-styrene type block copolymer was obtained. The block copolymer obtained was hydrogenated by using Pd/C (palladium carbon) in cyclohexane with hydrogen pressure of 2.1 MPa and reaction temperature of 100° C. to obtain the hydrocarbon-based polymer-2. The hydrocarbon-based polymer-2 obtained has a weight average molecular weight of 100,400, styrene content of 18% by mass, and hydrogenation ratio of 99 mol %.

Provenance & Evidence