Styrene → 2-Methylbuta-1,3-diene;styrene

HRID 1378544Notes

Reaction equation

HRID 1378544 reaction equation
C1CCCCC1.O1CCCC1.[CH2:12]=[CH:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.C([Li])CCC>CCCCCC>[CH2:12]=[CH:13][C:14](=[CH2:15])[CH3:19].[CH2:12]=[CH:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

6

Reactant 4

HCID 7501StyreneHCID 8028TetrahydrofuranHCID 8078CyclohexaneHCID 178418339Butyllithium

Product 1

HCID 1599892-Methylbuta-1,3-diene;styrene

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Conditions

Temperature
50 °C

Procedure

700 grams of cyclohexane containing 100 ppm of tetrahydrofuran and 18 g of styrene monomer were charged to a reactor of 2 litres of capacity, of stainless steel, equipped with thermostatting jacket and stirring system. The mixture was heated up to 50° C. and then 0.09 g of n-butyl-lithium in solution in n-hexane was added to it. After 25 minutes of reaction, the temperature had increased up to 55° C. A sample was collected in order to check the reaction mixture for the complete conversion of the monomer into polymer and measure the molecular weight, then 72 g of isoprene was added and the polymerization was allowed to proceed during 20 minutes; after that time period, the second monomer was completely converted. The temperature of the mixture resulted to be of approximately 90° C. Thus, a living diblock styrene-isoprene (S-I) polymer was obtained, which was then submitted to coupling in order to form a three-arm radial polymer.

Workup

  1. customequipped with thermostatting jacket
  2. customAfter 25 minutes of reaction
  3. temperaturethe temperature had increased up to 55° C
  4. customA sample was collected in order
  5. addition72 g of isoprene was added
  6. customThe temperature of the mixture resulted
  7. customto be of approximately 90° C

Sources & evidence

ORD record
ord-a2dd9f23c2a247e587d21eca2b826c62
Source dataset
uspto-grants-1997_09
Patent number
US05668208

Reaction notes

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