Acetic Acid → Isoprene butadiene

HRID 1956733Notes

Reaction equation

HRID 1956733 reaction equation
[CH2:1]=[CH:2][C:3](=[CH2:5])[CH3:4].[CH2:6]([Li])[CH2:7][CH2:8][CH3:9].C=CC=C.C(O)(=O)C>O1CCCC1.CCCCC>[CH2:1]=[CH:2][C:3](=[CH2:4])[CH3:5].[CH2:6]=[CH:7][CH:8]=[CH2:9]

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 6557IsopreneHCID 78451,3-Butadiene2×HCID 178418339Butyllithium2×

Product 1

HCID 168288Isoprene butadiene

Reagents, catalysts & solvents 2

HCID 8003PentaneSolventHCID 8028TetrahydrofuranSolvent

Procedure

A 5-gallon reactor was charged with 10.1 L of purified pentane under an inert atmosphere. To the reactor was added 632.5 g (9.29 mol) of purified isoprene, 62.2 ml of anhydrous tetrahydrofuran, and 10.0 ml of 2,2'-dipyridyl solution (0.1M) via a Hoke bomb. The reactor contents were heated to 50°-55° C. and titrated to a yellow-brown endpoint color with 1.6M n-butyllithium. The catalyst 1.6M n-butyllithium (263.5 ml, 0.421 mole) was then added to the reactor using a Hoke bomb. The polymerization reaction temperature was maintained between 50°-55° C. for 1 hour then cooled to 45°-50° C. At this time, 3584 g (66.4 mol) of freshly distilled butadiene was added. The polymerization continued for 0.5 hours, after which time 25.3 g (0.421 mol) of acetic acid was added. The molecular weight (Mn) was found to be approximately 10,000. An infrared analysis (FTIR) showed the butadiene microstructure to contain 55% 1,2- and 45% 1,4-microstructure.

Workup

  1. temperatureThe reactor contents were heated to 50°-55° C.
  2. customThe polymerization reaction temperature
  3. temperaturewas maintained between 50°-55° C. for 1 hour
  4. temperaturethen cooled to 45°-50° C

Sources & evidence

ORD record
ord-db6ebfc8fe8c41b9b936fdcf39c716e9
Source dataset
uspto-grants-1998_07
Patent number
US05780540

Reaction notes

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