Styrene → Styrene-butadiene-styrene

HRID 496973Notes

Reaction equation

HRID 496973 reaction equation
[CH:1]([Li])([CH2:3][CH3:4])[CH3:2].[CH2:6]=[CH:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.O1CCCC1.C=CC=C>C1CCCCC1>[CH2:6]=[CH:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.[CH2:2]=[CH:1][CH:3]=[CH2:4].[CH2:6]=[CH:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1

Participants

6

Reactant 4

HCID 7501Styrene2×HCID 78451,3-ButadieneHCID 8028TetrahydrofuranHCID 178418400CID 53628100

Product 1

HCID 22280236Styrene-butadiene-styrene

Reagents, catalysts & solvents 1

HCID 8078CyclohexaneSolvent

Procedure

In a 200 L pressure-resistant vessel filled with dry nitrogen, 75 kg of cyclohexane as a solvent and 45 g of sec-butyllithium as a polymerization initiator were added and, subsequently, 6.4 kg of styrene was added. After polymerization at 50° C., 0.21 kg of tetrahydrofuran as a Lewis base was added and, subsequently, 29.6 kg of butadiene and 6.4 kg of styrene were added in this order. When polymerization was carried out, a triblock copolymer of styrene-butadiene-styrene type was obtained. The block copolymer had a branching degree (α) of 0.154. The block copolymer obtained was subjected to hydrogenation at a hydrogen pressure of 2 MPa and a reaction temperature of 100° C. in cyclohexane using Pd/C as a catalyst. The reaction was carried out while sampling the reaction system at certain time intervals and the reaction was stopped in a stage where the ratio of hydrogenation of the hydrogenated block copolymer has become 52 mol %, yielding a styrene-hydrogenated butadiene-styrene block copolymer (SEBS). The resulting block copolymer had a weight average molecular weight of 100400 and a styrene content of 30% by weight.

Workup

  1. customAfter polymerization at 50° C.
  2. customWhen polymerization

Sources & evidence

ORD record
ord-64b14889a3af434f89169e006ed004bd
Source dataset
uspto-grants-2005_09
Patent number
US06949298B2

Reaction notes

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